RU215413U1 - AIRCRAFT NOSE FAIRING - Google Patents

Abstract

The utility model relates to an aircraft nose fairing device having radio transparency properties with the ability to quickly open and lock in the open position with a compact single-loop suspension assembly. A frame (3) is integrated along the contour of the fairing (2), to which the lower part of the hinge assembly (4) is fixed by means of a bolted connection, and the lower part of the hinge assembly (4) contains an adjustment assembly (9), which contains guides connected by jumpers (10) (11), in which elliptical holes (12) are made, intended for bolted connection. The upper part of the hinge assembly (4) is bent and provided with lugs (6), in the holes of which rods (8) are installed, which are movably fixed in mating brackets (18) on the fuselage (1) and fixed with fixation elements (7). Rods (13) are pivotally fixed on the inside of the frame (3), copper tires (16) are fixed on the fairing (2) from the outside. EFFECT: increased reliability of the fairing. 4 w.p. f-ly, 10 ill.

Description

The utility model relates to the field of aircraft engineering, more specifically to the device of the nose cone of an aircraft, which has the property of radio transparency with the ability to quickly open and lock in the open position with a compact single-loop suspension unit, and can be used in the design of helicopters.

A device for fastening the fairing of an aircraft is known (patent DE 602005004839, B64C 1/36, publ. 12.02.2009), which has a set of fasteners, each of which provides positioning of the fairing along two different axes lying in a plane perpendicular to the longitudinal axis of this fastening, each from a set of fasteners provides positioning of the fairing along one axis of the plane perpendicular to the longitudinal axis of this fastener, while the fasteners are located inside the fairing. A pin is attached to the frame of the fuselage of the aircraft, which has a concave part that complements the convex part, and a cylindrical part that can be inserted into a hole in the hull frame. The size of the mounting gap can reach several millimeters. The mounting gap allows mounting the fairing 2 on the fuselage 1 of the aircraft, avoiding the creation of mechanical stresses in this fairing even when the fairing is deformed, in particular due to the fact that the material of which the fairing consists is more flexible and deformable than the fuselage structure, to which this fairing attached. Each second mount positions the fairing relative to the fuselage along the longitudinal axis L of this second mount. The fairing may have on its outer surface metal strips used to drain into the body 1 currents caused by lightning strikes into this fairing.

The design of the fastening element of the protective fairing is known (patent EP 2724417, B64C 1/36, publ. 12.08.2015), in which the opening system has a fixed part and a movable part, consisting of movable mechanical elements that determine the rectilinear, lateral circular or rotary opening kinematics . The nose of aircraft A consists of a radome 2 made of a composite dome capable of protecting the radar antenna. The fairing 2 is connected to the fuselage 1 of the aircraft A, this fuselage being a fixed part. The fairing and fuselage are connected by fasteners 11 and centering elements 12 to facilitate installation.

A four-lever mechanism for opening a radar radome of an aircraft is known (CN patent 104512556, B64D 47/00, publ. 04/15/2015), which contains a tape fixed element, a U-shaped movable element, a tape straight connecting rod and a V-shaped curved connecting rod, with one end the tape fixed element is fixed on the aircraft body, and the other end of the strip fixed element is pivotally connected to one end of the strip straight connecting rod; the other end of the strip straight connecting rod is pivotally connected to one forked eye of the U-shaped moving element, the mounting surface of the U-shaped moving element is rigidly connected to the inside of the radar cover, the other fork of the U-shaped moving element is pivotally connected to one end of the V-shaped curved connecting rod , and the other end of the V-shaped bent connecting rod is pivotally connected to the middle forked ear of the strip fixed element.

A radio-transparent fairing is known that is closest to the claimed technical solution (patent RU 2090958, H01Q 1/42, publ. 09/20/1997), which is made of fiberglass in the form of a cap, an erosion-resistant tip made of a dielectric press material based on a fibrous silica filler and silicone binder. The erosion-resistant tip is connected to a cap made of fiberglass with glue, as well as to two metal pins located in a plane perpendicular to the plane of the electric vector of a linearly polarized antenna. This design of the radio-transparent radome makes it possible to reduce the direction-finding errors introduced by the antenna radome in determining the position of the target.

The disadvantage of the known device is the lack of the ability to quickly open for maintenance of radio equipment, insufficient reliability due to the lack of an integrated frame to provide the necessary rigidity in flight and lightning protection.

It is known that bionic (toponymic, generative) design is a method of designing various objects, in which solutions different from traditional ones are used to reduce weight and increase strength. Externally, objects produced in this way differ from ordinary man-made products. They have pronounced features inherent, for example, in plants, imitate the structure of limbs or bones. That is why this design method is often called bionic design. Another term, "generative design", is used due to the fact that the geometry of such structures is automatically calculated ("generated") in special software. The main task of bionic design is to reduce the weight of an object while maintaining (or increasing) the original strength (access mode https://3d.globatek.ru/world3d/generative_design/).

The technical problem solved by the claimed utility model is the creation of a radio-transparent nose fairing to protect the equipment located in the forward part of the fuselage from external factors, including lightning and precipitation, with a reliable fastening lock for fixing in the open and closed position, with the possibility of accurate positioning the fairing on the fuselage.

The technical result achieved by the claimed utility model is to increase the reliability of the structure during operation, through the use of a reliable locking system in the open and closed position with the ability to accurately position the fairing on the fuselage, increase reliability due to integrated lightning protection.

To achieve a technical result, an aircraft nose fairing 2 is proposed, containing a radio-transparent domed part 17 and fastening elements to the fuselage 1, in accordance with the claimed utility model, characterized in that a frame 3 is integrated along the contour of the fairing 2, to which the lower part of the assembly is fixed by means of a bolted connection hinges 4, and the lower part of the hinge assembly 4 contains an adjustment assembly 9, which contains guides 11 connected by jumpers 10, in which elliptical holes 12 are made, intended for bolted connection, while the upper part of the hinge assembly 4 is curved and provided with lugs 6, into the holes of which rods 8 are installed, which are movably fixed in reciprocal brackets 18 on the fuselage 1 and fixed by fixing elements 7, rods 13 are hinged on the inside of the frame 3, copper tires 16 are fixed on the fairing 2 from the outside.

At the same time, the aircraft nose fairing is made using prepreg vacuum molding technology.

In addition, the hinge assembly 4 has a shape selected by computer simulation to obtain minimum mass and maximum rigidity, made using additive technologies by selective laser melting from an aluminum alloy.

At the same time, the hinge assembly 4 is made in the form of two crankshafts 24 connected to each other by jumpers, which constitutes a spatial frame with a group of holes necessary to reduce weight while maintaining a given strength.

In addition, the fixing elements 7 are made in the form of washers with cotter pins.

Thus, the technical result is achieved - an increase in the reliability of the structure as a whole.

The use of a compact hinge assembly 4, the shape of which is made in the form of a spatial frame and provides rigidity in all directions, the presence of two lugs 6, into the holes of which the rods 8 are inserted, allows you to open the fairing 2, and the presence of rods 13 allows you to keep it in the open position.

The presence of a radio-transparent domed part of the fairing 17 is aimed at protecting the equipment from external factors.

The presence of four copper bars 16, attached to the fuselage 1 by metallization jumpers 15, provides protection against lightning, while their location and size do not interfere with the normal operation of the equipment.

The use of the adjustment unit 9, which contains guides 11 connected by jumpers 10, in which elliptical holes 12 are made, makes it easy to make accurate positioning and eliminate gaps, which prevents the penetration of moisture into the nasal compartment and increases the reliability of the structure as a whole.

The presence of the annular frame 3 allows the nose cone 2 to withstand the impact of birds at speeds up to 300 km/h, which increases reliability.

The design of the nose fairing is illustrated by drawings:

fig. 1 - nose fairing, general view;

fig. 2 is an inside view of the fairing and the hinge assembly;

fig. 3 is a side view of the fairing and the hinge assembly;

fig. 4 is a side view of the fairing and the hinge assembly;

fig. 5 is an inside view of the hinge assembly and the sealing contour;

fig. 6 - nose fairing, inside view;

Fig.7 - fairing in the open position;

fig. 8 - knot hinge nose cone in the closed position;

fig. 9 - knot hinge nose cone in the open position;

fig. 10 - diagram of the direction of electromagnetic waves.

In the forward part of the fuselage 1 of the helicopter, a radio-transparent fairing 2 is installed, which consists of a radio-transparent domed part 17 and a closed frame 3 integrated along the contour of the fairing 2, in other words, made together with it, which performs the function of a strength element of rigidity and gives strength to the structure (Fig. 1, 3, 5). Fairing 2 is made using prepreg vacuum forming technology. The lower part of the one-loop hinge assembly 4 (loop) is fixed to the frame 3 by means of a bolted connection, designed to fix the fairing 2 on the fuselage 1. At the same time, the hinge assembly 4 has a bionic shape, selected by computer simulation to obtain a minimum mass and maximum rigidity, is made with using additive technologies by selective laser melting of aluminum alloy. In addition, the hinge 4 is made in the form of a spatial frame, which ensures rigidity in all directions.

Initially, the shape of the hitch assembly 4 was determined in accordance with the kinematic scheme for opening the nose cone. After determining the profile, the attachment points were determined inside the fuselage and on the fairing 2 itself, and topological optimization was carried out in a special program in order to find and select the optimal shape of the frame of the hinge assembly 4 in accordance with the tasks and the general configuration of the fairing 2 and its placement on the fuselage.

The hitch assembly 4 is made in the form of two crankshafts 24 (figure 8, 9) when viewed from the side, interconnected by jumpers, which constitutes a spatial frame with a group of holes 5 of various shapes and sizes necessary to reduce weight (figure 2). The lower part of the bracket expands, and the guides take the form of “branches”, the expansion allows you to increase the shoulder for absorbing transverse loads and more evenly distribute forces when opening the fairing. The curved profile of the cranked shape 24 is necessary so that when opening the bracket does not touch the power frame (Fig.8, 9).

At the same time, the upper part of the hinge 4 is curved and provided with two lugs 6, in the holes of which the rods 8 are installed. .

On the other hand, the hinge assembly 4 contains the adjustment assembly 9 for precise positioning of the fairing 2 on the fuselage 1 (figure 2).

The adjustment unit includes reinforced guides 11, connected by diagonal bridges 10, which provide rigidity. The guides 11 are made oval (elliptical) holes 12 for the bolts 19 (figure 4). The oval (elliptical) shape of the holes 12 allows the fairing 2 to be displaced to ensure correct positioning and eliminate gaps. To fix the fairing 2 in the open or closed position, rods 13 are provided, which, on the one hand, are hinged on the inside of the integrated frame 3, and on the other hand, are fixed in the groove 20. On the frame 3, two rotary locks 21 of a typical design are fixed to fix the fairing 2 in closed position (figure 5). Mates for rotary locks 21 are installed on the fuselage 1. Two locks 22 are installed on the inside of the frame 3 and are designed to fix the rod 13.

Rods 13 can be made with gas springs (not shown) or with mechanical stops.

Along the contour of the fairing 2, four copper tires 16 are fixed on the outside, which are connected to the fuselage 1 using metallization jumpers 15, which provides protection against current in case of lightning strikes (Fig.5, 7).

The device works as follows.

In the process of pre-flight preparation, the operator unlocks the rotary locks 21 by turning 90 degrees, then raises the fairing 2 to service the equipment.

To lock in the open position, one end of the rod stop 13 must be released from the latch 22 and installed in the reciprocal groove of the bracket 20 on the fuselage.

To close the fairing, it is necessary to remove the stops of the rod 13 from the groove of the bracket 20, install the stop in the latch 22. Close the fairing 2, close the rotary locks 21 by turning 90 degrees (Fig.5, 6).

For positioning, loosen the bolts and move along the elliptical holes, then tighten the bolts.

The design of the assembly 4 for mounting and fixing in the open state allows servicing radio equipment at wind speeds up to 30 m/s.

In helicopter flight, the proposed design of the fairing 2 provides free transmission of electromagnetic waves perpendicular to the surface with minimal distortion in the frequency range from 1 to 10 GHz due to the elliptical shape of the radio-transparent domed part 17.

Figure 10 shows the Directional diagram of electromagnetic waves, which reflects the dependence of power loss (dB) on the angle of deviation of the electromagnetic wave (deg.) The graph shows that the calculated losses at different angles of radiation are less than 1 dB at the operating frequency, which meets the requirements of the terms of reference .

The locking mechanism, made in the form of a rotary lock 21 (figure 5), used in helicopter technology provides reliable locking in flight and prevents accidental opening. The seal 23 ensures the tightness of the compartment in the closed position and the exclusion of water from entering the equipment (Fig.4, 5).

Protection of equipment from lightning is implemented using copper tires 16 (figure 5). Lightning discharge occurs along copper busbars 16 through metallization jumpers 15 to the fuselage 1 (Fig.7).

The use of the utility model will improve the reliability of the fairing 2 due to the design of a compact hinge assembly and protection against lightning, provides a minimum opening-closing time for maintenance.

Claims (5)

1. Aircraft nose fairing (2), containing a radio-transparent domed part (17) and fastening elements to the fuselage (1), characterized in that a frame (3) is integrated along the fairing contour (2), to which the lower part is fixed with a bolted connection hinge assembly (4), wherein the lower part of the hinge assembly (4) contains an adjustment assembly (9), which contains guides (11) connected by jumpers (10), in which elliptical holes (12) are made, intended for bolted connection, while the upper the part of the hinge assembly (4) is curved and provided with lugs (6), in the holes of which the rods (8) are installed, which are movably fixed in the reciprocal brackets (18) on the fuselage (1) and fixed with fixation elements (7), from the inside of the frame ( 3) rods (13) are hinged, copper tires (16) are fixed on the fairing (2) from the outside. 2. Aircraft nose fairing according to claim 1, characterized in that it is made using prepreg vacuum molding technology. 3. Aircraft nose fairing according to any one of claims 1 or 2, characterized in that the hinge assembly (4) has a shape selected by computer simulation to obtain minimum mass and maximum rigidity, is made using additive technologies by selective laser melting from an aluminum alloy . 4. Aircraft nose fairing according to any one of claims 1-3, characterized in that the hitch assembly (4) is made in the form of two crankshafts (24) interconnected by jumpers, which constitutes a spatial frame with a group of holes necessary to reduce weight while maintaining a given strength. 5. Aircraft nose fairing according to any one of claims 1 to 4, characterized in that the fixing elements (7) are made in the form of washers with cotter pins.

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