Air intake for a motorized vehicle

[0002] The present invention relates to an air intake for a motorized vehicle, in particular for obtaining a low radar and infrared (“IR”) signature of a ballistically protected air intake of the vehicle, where a heat-emitting source in the vehicle is placed in immediate proximity to the air intake, comprising a perforated armour plate lying level with an outer bodywork plate of the vehicle, and a fresh-air duct which adjoins the inside of the perforated armour plate and which has a fan for sucking the fresh air necessary for running the vehicle into the duct via air intake openings in the armour plate.

[0003] In a combat vehicle driven by a combustion engine, in order to protect an air intake ballistically and at the same time to obtain a signature adjustment of same with respect to infrared, i.e. to give the air intake a low infrared signature, the air intake has previously been designed as an approximately 7-cm thick screen consisting of labyrinthine profiles which form air intake openings, so-called ballistic screens, which prevent direct viewing into the fresh-air duct and thus make it difficult to detect by infrared a heat-generating engine situated near the air intake. Such ballistic screens are very heavy and complicated to produce.

[0004] An object of the present invention is to make available a ballistically protected and signature-secured air intake for a motorized vehicle, where the perforated armour plate has a low height and weight and also a low signature with respect to both RR and infrared. For this purpose, said air intake according to the invention is characterized in that the fresh-air duct has an airflow-deflecting wall section situated between the air intake openings in the armour plate and the heat-emitting source, which wall section is provided with at least one air bypass duct for cooling the wall section. Since the design of said wall section means that it can be kept cooled during vehicle operation, this makes it difficult to detect by infrared cameras, and at the same time the perforation openings in the plate can be punched out easily as straight small holes in a relatively thin-walled armour plate with a thickness of only about 5 to 10 mm.

[0005] Said airflow-deflecting wall section can here be designed as a double wall with an air bypass duct in between, where one wall part of the double wall can be of anti-splinter design, preferably made of armour plate.

[0006] The air bypass duct is preferably connected upstream to a fresh-air intake and connected downstream to the fresh-air duct upstream of the fan.

[0007] To obtain a good RR signature on the outside of the perforated armour plate, a fine-mesh net with a mesh width of about 2 to 5 mm is preferably placed over the air intake openings in the armour plate.

[0008] The invention will be described in more detail below with reference to the attached drawing.

[0009] FIG. 1 is a diagrammatic side view of a ballistically protected and signature-adapted air intake according to the invention for a motorized combat vehicle; and

[0010] FIG. 2 is a cutaway perspective plan view of the air intake in FIG. 1, with a fine-mesh net placed over the air intake openings in the armour plate.

[0011] In FIG. 1, a ballistically protected fresh-air intake according to the invention for a motorized combat vehicle is designated in general by reference number 10. The air intake comprises a plane perforated armour plate 12 lying level with an outer, preferably upper bodywork plate 14 of the vehicle. The armour plate 12 has a thickness of about 5 to 10 mm, which permits simple punching out of air intake openings 16 with a diameter of the same order of size as the thickness of the plate 12.

[0012] Adjoining the inside of the perforated plate 12 is a fresh-air duct 18 in which a fan 20 (shown diagrammatically) can draw fresh air into the vehicle in order to provide the vehicle with air for the combustion of the fuel and for cooling of the engine (cooler 21) and possibly supply air to the crew areas. The duct 18 is angled immediately inside the perforated armour plate 12 by means of a wall section 22 which is situated between the plate 12 and a heat-emitting source, in this case a combustion engine 24. In order to reduce the infrared signature from the air intake, i.e. to make it difficult to detect with the aid of thermal imaging cameras directed towards the wall section 22 exposed via the air intake openings 16, it is later provided with at least one air bypass duct 26 which is designed to cool the wall section 22 to a temperature which gives a low infrared signature. The bypass duct 26 can be formed by a double wall consisting of an inner wall element 28 and an outer wall element 30, the latter preferably being made of armour plate or other suitable anti-splinter material so that in the event of damage to the air intake 10 it will strengthen the fresh-air duct 18 and intercept splinters.

[0013] The upstream end of the bypass duct 26 can open into one or more intake openings 32 in the perforated armour plate 12 or into a separate intake at a distance from the plate 12, while the downstream end 34 of the duct 26 opens into the fresh-air duct 18 upstream of the fan 20, so that the latter can also suck cooling air into the bypass duct 26 in order to keep the wall section 22, and in particular the wall element 28 facing towards the perforated armour plate 12, cool and thus minimize the IR signature of the air intake which will otherwise be created by the adjacent heat-emitting engine 24.

[0014] In order also to minimize the RR signature of the air intake 10 and reduce the risk of detection by radar, a fine-mesh net 36 (mesh width about 2 to 5 mm) is placed on the outside of and over the air intake openings 16, 32, as is shown in FIG. 2.