DE102020005682B4 - fuel tank - Google Patents

Abstract

Fuel tank (12) having a bottom wall (14), a cover wall (16), a front wall (18), a rear wall (20) and two side walls (22, 24) containing steel walls (48, 50, 53, 52), which surround an inner space for containing fuel, the steel walls (48, 50, 52) being covered with a sealing material (54) which, in the event of a leak occurring as a result of a projectile impacting the steel walls (48, 50, 52) of the filled Fuel tanks (12) can be expanded by contact with the fuel escaping from the fuel tank (12) and the leak in the affected steel wall (48, 50, 52) can thereby be sealed, characterized in that in the interior of the fuel tank (12) ballistic protective plates (28 , 30, 32, 34) are provided, which extend parallel to the steel walls (48, 52) exposed to projectile impacts at a distance from them, and that in the interior of the fuel tank (12) and in the spaces between the ballistic protection plates (28, 30 , 32, 34) and de Filling bodies (62, 64) made of expanded metal are arranged in intermediate spaces formed in steel walls (48, 52).

Description

The invention relates to a fuel tank with a bottom wall, a cover wall, a front wall, a rear wall and two side walls containing steel walls which surround an interior space for containing fuel, the steel walls being covered with a sealing material which, if a leak occurs as a result of a Impact of a projectile in the steel walls of the filled fuel tank can be widened by contact with the fuel escaping from the fuel tank and the leak in the affected steel wall can be sealed as a result.

Such a self-sealing fuel tank for a military vehicle is from WO 2006/076030 A2 known. The multi-layer coating features a layer of beaded absorbent bodies that swell significantly on contact with fuel, working in tandem with a compression layer to seal a leak caused by small caliber bullet impact.

In the U.S. 9,127,915 B1 describes a self-healing composite material that can withstand multiple impacts without significant degeneration of the material as an alternative to expensive and heavy antiballistic materials. A projectile's kinetic energy is converted to heat which causes melting of a polymer filling the projectile trajectory and capable of trapping the projectile in a polymer matrix, provided the projectile's energy is limited.

In the WO 2011/047863 A2 describes how fuel tanks on vehicles can be filled with a network of thin metal foils or metal fibers in order to make use of the principle of the Davy safety lamp from the field of mining.

Means for protecting a fuel tank from focused radiant energy in the military field are disclosed in US Pat DE 696 37 070 T2 revealed. A barrier layer in the form of a sleeve or cover is placed around the object to be protected. The barrier layer consists of layers of slit expanded metal foils, whereby nested ellipsoids can be present between layers of expanded metal. The barrier layer dissipates the incident energy upon striking the slit stretch film made of a non-ferrous metal with low absorptivity and high thermal conductivity, thereby delaying penetration of a laser beam.

From the EP 3 140 194 B1 An aircraft fuel tank for accommodating a fuel has become known, the tank lining of which has spherical elements whose hardness value has a higher hardness value than a binding material surrounding them. When a projectile penetrates the tank lining, the collision of the projectile with the hard elements can prevent the projectile from also penetrating the tank lining opposite the point of impact if the projectile energy is below predetermined limit values.

A method for the production of packing as explosion protection for fuel tanks is from DE 38 16 792 A1 known. Expanded metal with high thermal conductivity is used to produce spherical fillers. Filling bodies of a specific shape and size are produced from essentially two-dimensional lattices by deforming. Containers containing liquid explosive substances can be subsequently filled with such filling bodies. If such a container ignites, there is no explosion of the explosive gases that have accumulated in the container space, but instead the container contents burn off normally in a controlled manner.

It is known that most armored vehicles, especially combat vehicles, are lost not from a direct hit by a projectile, but from a hit by a fuel tank and the subsequent explosion of the fuel tank. For this reason, especially in military vehicles, fuel tanks are protected in that their walls are designed as solid steel walls against which an impacting projectile is intended to ricochet. In order to prevent an impacting projectile from entering the fuel tank and triggering secondary explosions and fires there, very thick steel walls are often used for fuel tanks, so that the weight of the vehicle to be protected increases considerably.

Proceeding from the prior art discussed above, the object of the invention is to create a fuel tank which has steel walls and which enables a high weight saving compared to an armored fuel tank made of steel, in which projectiles with high projectile energy are also prevented from destroying the fuel tank must.

This object is achieved with a fuel tank having a bottom wall, a cover wall, a front wall, a rear wall and two side walls containing steel walls which surround an inner space for containing fuel, the steel walls being covered with a sealing material which, when a leak occurs, as a result a projectile hitting the steel walls of the filled fuel tank by contact with the from the fuel tank escaping fuel and thereby the leak in the affected steel wall can be sealed is solved by the fact that ballistic protective plates are provided in the interior of the fuel tank, which extend parallel to the steel walls exposed to the projectile impacts at a distance from them, and that in the interior of the fuel tank as well as in Filling bodies made of expanded metal are arranged in the gaps formed between the ballistic protection plates and the steel walls.

If a projectile or other projectile hits the fuel tank, it is provided that this can penetrate into the interior of the fuel tank. For this reason, thick steel walls associated with very high weight are not necessary, but light steel walls whose thickness is not sufficient to let a projectile ricochet off them.

If a leak occurs as a result of a puncture in a steel wall, fuel escapes, which reacts with a sealing material applied to the affected steel wall in such a way that it closes and seals the leak that has just occurred. The projectile that penetrated into the interior of the fuel tank is decelerated in the interior of the fuel tank by the packing made of expanded material and finally hits one of the ballistic protection plates provided in the interior of the fuel tank with greatly reduced energy, which are arranged at a distance parallel to the steel walls. For this reason, the decelerated and deformed projectile is prevented from leaving the fuel tank opposite the point at which a projectile hit the ground. It is retained inside the fuel tank and prevented from destroying the fuel tank.

In an expedient exemplary embodiment of the fuel tank, a polycarbonate layer is arranged on the side of the sealing material pointing away from the steel wall, which in turn is covered by a protective layer made of polyurethane on the side pointing away from the sealing material.

An air gap is preferably provided between the sealing material and the polycarbonate layer, which has a width of between 0.5 and 2 millimeters, preferably 1 millimeter. In this way a good sealing of a leak in a steel wall hit by a projectile is achieved.

The polycarbonate layer preferably has a thickness between 8 and 16 millimeters. It is expedient if a protective layer made of polyurethane is provided on the polycarbonate layer, which has a thickness of between 1 millimeter and 5 millimeters, preferably 3 millimeters.

The fuel tank may have the shape of a polyhedron, with the ballistic protection plates each extending along planes spaced 6 to 12 centimeters from the steel side walls.

In order to achieve good protection against projectiles arriving at an angle in the area of the corners of the fuel tank, it is provided that the ballistic protection plates intersect along lines which are parallel to the edges of a fuel tank extending between the steel wall on the bottom side and the steel wall covering the fuel tank fuel tanks having the shape of a polyhedron.

For effective protection, it is useful if the ballistic protection plates are made of steel that is characterized by a high yield point and high hardness. The ballistic protection plates have a wall thickness between 3 millimeters and 6 millimeters, preferably 4.5 millimeters, in order to still be able to meet high security requirements with a significant weight saving.

The steel walls of the protective device's fuel tank have a thickness of 3 millimeters to 6 millimeters, preferably 4.5 millimeters.

The sealing material provided for sealing the steel walls is preferably glued to the steel walls and generates a self-healing foam when it comes into contact with escaping fuel, so that only a relatively small amount of fuel will escape in the event of a bullet.

The filler bodies, which fill the space inside the fuel tank primarily intended for fuel, preferably consist of expanded metal made of aluminum foil. They may consist of ribbons rolled up into coils. Alternatively, the packing may be in the form of ribbons or spheres. The filling bodies are preferably each surrounded by a stainless steel mesh in order to enable easier handling.

The expanded metal for the production of the packing is preferably a ribbed expanded metal made of aluminum or an aluminum alloy, the thickness of which is in the range from 0.05 to 0.3 millimeters.

It is particularly expedient if the filling bodies have the shape of a cylinder or a mat and are shrunk into a stainless steel mesh serving as a mesh.

In order to weaken the pressure wave generated in the tank when a projectile hits it, it is expedient if the fuel tank has a pressure relief valve through which fuel can escape if the fuel tank is hit by a projectile which causes a shock wave in the fuel tank.

Further advantageous configurations and alternatives are described in more detail in the following description of an exemplary embodiment of the invention with reference to drawings.

• 1 ein Kampffahrzeug mit an seinem Heck angeordneten Kraftstofftank in einer schematischen Darstellung,
• 2 eine schematische Ansicht eines Kraftstofftanks gemäß einem Ausführungsbeispiel der Erfindung in einer perspektivischen Ansicht,
• 3 eine der 2 entsprechende schematische Darstellung des Kraftstofftanks mit gestrichelt dargestellten Rändern von im Inneren des Kraftstofftanks angeordneten ballistischen Schutzplatten,
• 4 eine schematische Darstellung des Kraftstofftanks in einer perspektivischen Ansicht nach Abnahme einer Seitenwand für einen Blick in das Innere des Kraftstofftanks vor dem Befüllen des Kraftstofftanks mit Füllkörpern,
• 5 einen Querschnitt durch die Wandung des Kraftstofftanks zur Veranschaulichung der Schichtenfolge der Wandung und
• 6 eine schematische Darstellung des Kraftstofftanks im Querschnitt parallel zu den Seitenwänden des Kraftstofftanks zur schematischen Veranschaulichung des Innenraums des Kraftstofftanks nach dessen Befüllung mit Füllkörpern.

Show it:

• 1 a combat vehicle with a fuel tank arranged at its rear in a schematic representation,
• 2 a schematic view of a fuel tank according to an embodiment of the invention in a perspective view,
• 3 one of the 2 Corresponding schematic representation of the fuel tank with edges of ballistic protection plates arranged inside the fuel tank shown in dashed lines,
• 4 a schematic representation of the fuel tank in a perspective view after removal of a side wall for a look inside the fuel tank before filling the fuel tank with fillers,
• 5 a cross section through the wall of the fuel tank to illustrate the layer sequence of the wall and
• 6 a schematic representation of the fuel tank in cross section parallel to the side walls of the fuel tank to schematically illustrate the interior of the fuel tank after it has been filled with filling bodies.

a in 1 Schematically illustrated, armored multi-axle combat vehicle 10 has at its rear a fuel tank 12 with, for example, a capacity of 250 liters for driving engines, generators and heating systems of the combat vehicle 10. The fuel tank 12 has a bottom wall 14 and a cover wall 16 opposite this. Next can be seen in a schematic representation in 1 the front wall 18. In addition, the fuel tank 12 has a rear wall 20 and two side walls, of which the left side wall 22 in 1 is illustrated.

When using in 1 Schematically illustrated combat vehicles 10, most combat vehicles 10 are not lost by a direct hit, but by hitting the fuel tank 12 with the subsequent explosion of the fuel tank 12 and subsequent secondary explosions and fires. In order to reduce this risk, the fuel tank 12 according to an embodiment of the invention has a protective device based on the 2 until 6 is described in more detail below.

2 12 is a schematic perspective view of the fuel tank 12 without, for the sake of simplicity, filler necks, connections for the circulation of the fuel for warming up, and without the provision of a pressure-relief valve, as well as thermal radiation-retaining arrangements to avoid detection by infrared rays.

In 2 shows the schematic view of the fuel tank 12 in the form of a polyhedron. Instead of the in 2 illustrated geometry of the fuel tank 12, this can also have other geometries. The shape of the fuel tank 12 is particularly simple if, in accordance with 2 illustrated embodiment, the cover wall 16 extends parallel to the bottom wall 14. the inside 2 A right side wall 24 is correspondingly assigned to the left side wall 22 shown. Between the left side wall 22 and the right side wall 24 extends in 2 the rear wall 20. While the left side wall 22 and the right side wall 24 are arranged substantially parallel to one another, the front wall 18 and the rear wall 20 are inclined towards one another. The left side wall 22 and the rear wall 20 form a rear left edge 26 as seen in the direction of travel of the combat vehicle 10.

The schematic representation in 3 FIG. 12 shows the fuel tank 12 to show the arrangement for preventing a projectile that has penetrated the cabin from exiting the fuel tank 12, which would cause a dangerous situation.

Extending parallel to left sidewall 22 is a left ballistic protection panel 28, illustrated in phantom. Similarly, extending parallel to right sidewall 24 is a right ballistic protection panel 30. In order to suppress the exit of a projectile in the direction of front wall 18, a front ballistic protection panel 32 intended. A rear ballistic protection plate 34 is arranged parallel to the rear wall 20 .

The ballistic protection plates 28, 30, 32 and 34 consist of safety steel with a yield point of 1400 N/mm ² . Hardness values between 470 and 540 HB are appropriate. The tensile strength of the preferred belay used steel is 1750 N/mm ² . The elongation at break of the material used is 7 percent.

Since the ballistic protection panels 28, 30, 32, 34 extend their entire length parallel to the lengths of the side walls 22, 24 and the front wall 18 and rear wall 20, the ballistic protection panels 28, 30, 32 and 34 intersect along in 3 lines not shown which are parallel to the edges 36, 38 and 40. The distances of the ballistic protection plates 28, 30, 32 and 34 from the associated side wall 22, side wall 24, front wall 18 or rear wall 20 is 6 to 12 centimeters. In this way, a gap of about 6 to 12 centimeters is created between the respective steel walls 48, 50, 52 in the front wall 18, the rear wall 20, the left side wall 22 and the right side wall 24 and the associated ballistic protection plates 28, 30, 32, 34

The arrangement of the front ballistic protection plate 32 and the rear ballistic protection plate 34 is shown in FIG 4 clarified. In particular, one recognizes in the sectional view of 4 the front gap 42 between the front wall 18 and the front ballistic protection plate 32. Also in FIG 4 It can be seen that there is a gap 44 between the rear ballistic protection panel 34 and the rear wall 20 . Corresponding in 4 Intermediate spaces, not shown, are located between the left side wall 22 and the left ballistic protection plate 28 and the right ballistic protection plate 30 and the right side wall 24. In the case of FIG 4 illustrated embodiment, no ballistic protection plates are provided parallel to the bottom wall 14 and parallel to the cover wall 16 .

the 5 is not to scale in cross-section along line VV of FIG 4 the layer sequence of the shell of the fuel tank 10 using the example of the front wall 18. The front wall 18 has a front steel wall 48 which is part of the basic structure of the fuel tank. The bottom wall 14 has a steel lower wall 50 and the rear wall 20 has a steel rear wall 52.

The steel walls 48, 50, 52 have a wall thickness of 3 millimeters to 6 millimeters, preferably 4.5 millimeters. They have a high yield strength and hardness. The yield point is preferably around 1200 N/mm ² and the hardness around 450 HB.

How from the 4 and 5 a sealing material 54 can be seen on the steel walls 48, 50 and 52. The sealing material 54 is glued onto the respective steel wall 48, 50 and 52. It is made of a composition that reacts with fuel to form a self-healing foam to plug holes in the fuel tank 12. The thickness of the sealing material 54 is preferably 22 millimeters and is therefore several times thicker than the thickness of the associated steel wall 48, 50, 52.

5 shows that the sealing material 54 is in turn covered by a polycarbonate layer 56 to the outside. Between the polycarbonate layer 56 and the sealing material 54 there is an air gap 58 with a thickness of about 1 millimeter. The polycarbonate layer 56 has a thickness of approximately 12 millimeters and is in turn covered by a protective layer 60 .

The protective layer 60 consists of polyurethane and has a thickness of approximately 3 millimeters.

The layer sequence described above is identical for the front wall 18, the bottom wall 14, the rear wall 20 and the left side wall 22 and the right side wall 24.

5 12 further illustrates front ballistic protection plate 32 spaced from front steel wall 48 in addition to the laminations described above. The spacing between front steel plate 48 and front ballistic protection plate 32 is as shown in FIGS 5 and 6 shown, filled by packing 62. Correspondingly, filler bodies 62 are located between the ballistic protection plates 28, 30, 32 and 34 and the associated steel walls 48, 50, 52.

In addition to the filler bodies 62, there are a plurality of filler bodies 64 inside the fuel tank. The filler bodies 62 and 64 are preferably made of ribbed expanded metal with a thickness of 0.7 millimeters. The arrangement is particularly expedient if the filling bodies 62, 64 consist of windings which are provided in different sizes and are shrunk into a stainless steel mesh or mesh. The filler bodies 62, 64 fill the entire volume of the fuel tank 12 for the desired suppression of an explosion. This results in a volume loss of the contents of the fuel tank 12 of about 2 to 3 percent. In addition to suppressing the explosion, the filling bodies 62, 64 have an additional effect with regard to minimizing the surge effect when the vehicle is moving.

The filling bodies 62, 64 can in particular be designed as cylinders or mats. Due to the fact that the filling bodies 62, 64 are provided, a particularly effective deceleration of the projectile takes place after the outer layer has been penetrated by a projectile. The hydrodynamic wave of the fuel created by the kinetic energy is thereby significantly reduced by the packing 62, 64, regardless of whether they are designed as a coil or mat.

in the in 6 The cross section shown parallel to the side walls of the fuel tank 12 shows the filler bodies 62, 64 distributed in the interior of the fuel tank 12. After the fuel tank 12 has been filled, these are completely surrounded by fuel and reduce the volume of the interior of the fuel tank 12 by only a few percent.

Claims (15)

Fuel tank (12) having a bottom wall (14), a cover wall (16), a front wall (18), a rear wall (20) and two side walls (22, 24) containing steel walls (48, 50, 53, 52), which surround an inner space for containing fuel, the steel walls (48, 50, 52) being covered with a sealing material (54) which, in the event of a leak occurring as a result of a projectile impacting the steel walls (48, 50, 52) of the filled Fuel tanks (12) can be expanded through contact with the fuel escaping from the fuel tank (12) and the leak in the affected steel wall (48, 50, 52) can thereby be sealed, characterized in that in the interior of the fuel tank (12) ballistic protective plates (28 , 30, 32, 34) are provided, which extend parallel to the steel walls (48, 52) exposed to projectile impacts at a distance from them, and that in the interior of the fuel tank (12) and in the spaces between the ballistic protection plates (28, 30 , 32, 34) and d Filling bodies (62, 64) made of expanded metal are arranged in intermediate spaces formed in steel walls (48, 52). fuel tank (12) after claim 1 , characterized in that a polycarbonate layer (56) is arranged on the side of the sealing material (54) pointing away from the steel wall (48, 50, 52). fuel tank (12) after claim 2 , characterized in that between the sealing material (54) and the polycarbonate layer (56) an air gap (58) is provided which has a width between 0.5 and 2 millimeters. fuel tank (12) after claim 2 or 3 , characterized in that the polycarbonate layer (56) has a thickness between 8 millimeters and 16 millimeters. Fuel tank (12) according to one of claims 2 until 4 , characterized in that a protective layer (60) made of polyurethane is provided on the polycarbonate layer (56). fuel tank (12) after claim 5 , characterized in that the protective layer (60) made of polyurethane has a thickness between 1 millimeter and 5 millimeters. A fuel tank (12) according to any one of the preceding claims, characterized in that the fuel tank (12) has the shape of a polyhedron and that the ballistic protection plates (28-34) extend along planes which are a distance of 6 to 12 centimeters from the associated steel walls (48-52). fuel tank (12) after claim 7 , characterized in that where the two side walls (22, 24) are connected to the front wall (18) and the rear wall (20), respectively, edges (36, 38, 40) of the fuel tank (12) are formed, and that the Planes of the ballistic protection panels (28, 30, 32, 34) intersect along lines parallel to the edges (36, 38, 40). Fuel tank (12) according to one of the preceding claims, characterized in that the ballistic protection plates (28, 32, 34) consist of a steel which has a yield point of 1400 N/mm ² and a hardness of 470 to 540 HB. Fuel tank (12) according to one of the preceding claims, characterized in that the ballistic protection plates (28, 32, 34) have a wall thickness between 3 millimeters and 6 millimeters. Fuel tank (12) according to one of the preceding claims, characterized in that the steel walls of the fuel tank (12) have a thickness of 3 millimeters to 6 millimeters. Fuel tank (12) according to one of the preceding claims, characterized in that the expanded material for producing the filling bodies (62, 64) is a ribbed expanded metal made of aluminum or an aluminum alloy, the aluminum having a thickness of 0.05 to 0.3 millimeters. Fuel tank (12) according to one of the preceding claims, characterized in that the filler bodies (62, 64) have the shape of a cylinder or a mat and are shrunk into a stainless steel mesh serving as a mesh. Fuel tank (12) according to any one of the preceding claims, characterized in that the fuel tank (12) has a pressure relief valve through which fuel can escape when the fuel tank (12) has been hit by a projectile causing overpressure. A fuel tank (12) according to any one of the preceding claims, characterized in that the fuel tank (12) has lines for filling and emptying and circulating fuel and an infrared radiation suppressing camouflage cover.

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