EP0402713B1 - Gun barrel made of fibre-reinforced plastic - Google Patents

Description

The invention relates to a weapon barrel made of fiber-reinforced plastic with fibers laid orthogonally to one another over the entire length of the barrel in the axial and circumferential directions, having an ignition plane perpendicular to the barrel axis, in which at least one firing barrel with an igniter tube head is located, this area on the barrel of one Ignition ring is surrounded.

The use of gun tubes made of fiber-reinforced plastic is known, for example, from anti-tank handguns from DE-A-3 048 596. Such gun barrels can temporarily absorb pressures of 10⁸Pa (1000 bar) and more. In these, two holes are preferably made in the wall of the gun barrel to ignite the propellant charge. Due to their construction, they lie on a common length coordinate close to each other in a plane perpendicular to the gun barrel axis. This level is called the ignition level. In addition to axially extending glass fibers, these holes also cut previously closed glass fiber ring layers, which means that in particular the circumferential strength or radial expansion in the area of the ignition level are no longer determined primarily by the tensile strength of the glass fibers, but rather by the dimensional stability of the glass-resin composite part . In the event of extreme pressure loads, intermediate fiber breaks, particularly in the area between the bores and in the vicinity thereof, cannot be ruled out. Instead of the glass fibers used with preference, fibers made of carbon, aramid or the like can also be used. be used.

The invention is based, in particular to increase the circumferential strength of the weapon barrel and its bond with the at least one ignition tube, the task.

The object is achieved by a weapon barrel of the type mentioned at the outset, which is characterized in that a bead is present on the weapon barrel in the region of the ignition level, the Contour - viewed in section through the gun barrel axis - is similar to a circular section and on which additional fibers are laid in a wave shape, which penetrate the lighting level at an angle between 15 and 25 °, and the at least one lighting tube is only anchored in the wall of the gun barrel and the lighting tube head is one has radial sliding possibility in the ignition ring with respect to the weapon barrel axis.

Here one has freed oneself from the idea that in weapon tubes for anti-tank weapons the usually metallic ignition ring should help to absorb voltage peaks in the circumferential direction. It has been shown that it can even be disadvantageous if there are two fixed points for the ignition tube, one in the wall of the weapon tube and additionally one outside in the ignition ring. Because of the different spreading of the pressure waves in the metal and in the fiber-plastic composite, the connection of the ignition tube to the ignition ring is subject to a very considerable load for a short time; the partially severed fibers fail to absorb the tensile load and the shear strength at the fiber / resin interface alone may then not be able to withstand the short-term load. The connection of the firing tube with the weapon barrel can also be adversely affected by the fact that, due to a further fixed point on the head of the firing tube, further stress peaks and shear stresses can occur. By combining the measures according to the invention, these effects are completely eliminated.

The direct rigid connection of the head of the ignition tube to the ignition ring prevents, as long as it is not destroyed, propellant gases escaping in the area of the ignition ring. However, such a seal can also be implemented in a very simple manner using elastic means, for example an O-ring. Changing the winding around the ignition hole enables mechanical decoupling between the ignition tube and the ignition ring.

The inventive attachment of the firing tube in the gun barrel and firing ring allows considerably greater manufacturing tolerances in the diameter of the firearm and firing ring. Especially when manufacturing on NC processing machines, this leads to considerably longer tool life.

Before the wavy course of the fiber rovings is formed, the area of the weapon barrel, in which the ignition ring is later to be arranged, is preferably first provided with some additional, essentially circumferential application layers, approximately the width of the ignition ring, of the order of five times as wide as that Diameter of the hole for the ignition tube in the gun barrel. Further fiber rovings are then applied to this area in such a way that an annular bead is formed which, viewed in an axial section through the weapon barrel, has an outer contour similar to a circular section. This formation of the bead then makes it possible to lay the fibers approximately sinusoidally on it, the “wavelength” being greater or smaller than the tube circumference in order to ensure an offset of the individual fiber layers relative to one another. If the wavelength is chosen too large, numerous fibers are cut when drilling the hole for the ignition tube; the number of closed ring layers passing through the bores is reduced, and with it the strength. If the amplitude is too large at the same wavelength, i.e. the angle measured between the tube axis and the fibers in the ignition plane is less than 65 °, then due to radial expansion between the wavy and the fibers laid underneath in the circumferential direction, such a great shear occurs that the two layers connecting resin no longer withstands them. Low is an angle between 15 and 25 °, preferably 20 ^°, to the fibers during the piercing of the Anzündebene form therewith. The fiber reinforcement of the weapon barrel, which is preferably used for anti-tank weapons, in particular anti-tank hand weapons, is preferably made of glass fibers. However, other fibers, as stated at the beginning, can also be provided.

Fig. 1

Bewicklung eines Waffenrohres im Bereich der Anzündebene;

Fig. 2

Schnitt durch ein in ein Waffenrohr eingesetztes Anzündrohr.

The invention is shown schematically in the drawing in one exemplary embodiment and is further described below by way of example. Show it:

Fig. 1

Wrapping a gun barrel in the area of the ignition level;

Fig. 2

Section through an ignition tube inserted into a gun barrel.

In the view of a section of the weapon barrel 1 according to FIG. 1, only the middle layer 2 in the axial direction 3 is indicated by the orthogonal glass fiber reinforcement; for the sake of clarity, the circumferential position above was not shown. The ignition level 4 lies approximately in the middle of the elongated weapon barrel 1 of an anti-tank weapon. This area is of particular importance insofar as two closely adjacent bores are usually provided for receiving two detonators that are independent of one another, and glass fibers are cut in the process. This has a particular effect on the glass fibers in the circumferential direction, especially between the two holes and in their vicinity.

According to the invention, the area around the two ignition bores 5 is specially wound in a width B. In practice, the value B is - in deviation from the drawing - preferably about five times as large as the diameter (for example about 3 mm) of a bore 5 and corresponds approximately to the width of the ignition ring which is fastened on the weapon barrel 1 via the bores 5 got to. The wave-shaped course in the area of the ignition level 4 is characteristic. Before the special winding 19 is started, a bulge 18 is generated, the outer contour 6 of which approximately has the shape of a circular section, as can be seen in the detail X of FIG. 1. The glass fibers 7 are then placed in a wave-like manner over the bead 18, the “wavelength” L, of which only a quarter is shown, on the circumference π. D of the gun barrel 1 should be matched that the scope is not an integer multiple of this wavelength. It is thus achieved that the glass fiber distribution also for this winding 19 is even over the circumference. The angle α at which the fibers 7 cross the ignition plane 4 is preferably 20 °.

1 is idealized insofar as only the important load-bearing, not cut fibers 7 are drawn around the bores 5. As such, winding is first carried out uniformly in waves and only then are the bores 5 made for receiving the ignition tubes. The cut and therefore not load-bearing fibers in the winding 19 have been omitted in FIG. 1 for clarification. It can be seen that a bore 5 is surrounded by the fibers 7 approximately as if it were a rhombus, which, when the tube is expanded in the radial direction, that is to say a train which causes the rhombus to lengthen, simultaneously leads to a narrowing of the rhombus and thus to one Pressing the fibers leads to the ignition tube.

Fig. 2 shows the connection of the ignition tube 10 with the gun barrel 1 under the ignition ring 12 in the ignition plane. The winding of the tube 1 is no longer shown; most of the glass fibers run essentially in the circumferential direction and parallel to the axis of the weapon barrel 1; it is important, however, that some of the fibers (of the order of about 15%) also run in a wave shape around the ignition tube 10, based on the ignition level.

The ignition tube 10 is positively connected to the weapon barrel 1 by a screw thread 13 by being screwed into its wall 11. Between the ignition ring 12 and the weapon barrel 1 is a relatively thick elastic layer 14 (a foam or an adhesive layer). It is important to have a sliding gap 15 between the ignition tube head 17 and the ignition ring 12. In this construction, an O-ring 16 is sufficient to prevent the escape of propellant gases; it does not lose its sealing effect if there is a sliding movement of the head 17 of the ignition tube 10 in the ignition ring 12.

Claims (4)

1. Weapon barrel of fibre reinforced plastics, with fibres (2) laid over the entire tube length in the axial and circumferential direction orthogonally to one another, having an igniter plane (4) lying at right angles to the axis of the weapon barrel (3), in which plane lies at least one igniter tube (10) with an igniter tube head (17), with this region being surrounded at the weapon barrel (1) by an igniter ring (12), characterised in that, there is provided on the weapon barrel (1) in the region of the igniter plane (4), an annularly-shaped bead (18) whose outer contour (6) - (seen in section through the axis of the weapon barrel) - is like a circular segment and on which are laid in the shape of waves further fibres (7) which intersect the igniter plane (4) with an angle (α) between 15 and 25° and the at least one igniter tube (10) is anchored only in the wall (11) of the weapon barrel (1) and the igniter tube head (17) has a possibility of radial sliding (15) in the ignition ring (12) relative to the axis of the weapon barrel (3).
2. Weapon barrel according to claim 1, characterised in that the igniter tube (10) is held in the weapon barrel (1) in form locking manner by means of a screw thread (13).
3. Weapon barrel according to claim 1 or 2, characterised in that an elastic seal, preferably an O-ring (16), is provided between the head (17) of the igniter barrel (10) and the igniter ring (12).
4. Weapon barrel according to claim 1, 2 or 3, characterised in that an elastic layer (14) is provided between the igniter ring (12) and the weapon barrel (1).

Images