ES2293809B1 - REAR SECTION OF THE FUSELAGE OF AN AIRPLANE. - Google Patents

Abstract

Rear section of the fuselage of an airplane, adapted for fixing the lifting stabilizer and the steering wheel of an airplane, which is constituted by a front section of the steering rudder (SA) and by a rear section of the lifting stabilizer (HA ) in the direction of flight (F), which are rigidly joined together; the steering rudder section (SA) comprises extreme frames (20, 40) with reinforcing braces aligned almost orthogonally with respect to each other; nodal points (KN, ZKN) of the reinforcement braces of the extreme frames (20, 40) are connected with space braces (RS) inclined with respect to the direction of flight (F).

Description

Rear section of the fuselage of an airplane.

The invention relates to a rear section of the essentially barrel-shaped fuselage, configured essentially as a load bearing structure, adapted for fixing the lifting stabilizer and the rudder direction, of an airplane with frames that extend in planes transversal, stringers that extend in the longitudinal direction and an outer covering with a transverse opening, which is extends essentially horizontal, for the passage of the stabilizer of elevation.

The rear section of the fuselage of an aircraft, especially a transport aircraft, in which a lifting stabilizer and a steering rudder are connected, requires high lift capacity due to the application of large forces from the stabilizers. Conventional configurations of the structure of such rear sections of the fuselage are oriented to the type of stringer construction
-Outdoor- exterior cladding with local application of stabilizer forces. These local applications of the forces lead to considerable local elevations of the tension, especially in the fragment of the fuselage of the lifting stabilizer and thus condition considerable thicknesses of the material and, therefore, again a considerable overweight. A heavier rear section of the fuselage also has the disadvantage of extending the center of gravity of the vehicle backwards. In this way, the static stability of the vehicle is worsened. The necessary compensation would be a displacement of the support surfaces (= of the lift point) backwards, which results in a reduction of the "aerodynamic lever" towards the stabilizers. Due to this reduction of the lever, larger surfaces of the stabilizers would be required to maintain the maneuverability of the vehicle, which would result in an increase in stabilizer forces and, therefore, reinforcement and elevation. of the weight of the fuselage section structure.

Therefore, the problem of the present invention is to configure the rear section of the fuselage of an airplane according to the preamble of claim 1 of the patent, of such so that the distribution is as uniform as possible of the forces applied by the stabilizers over the entire structure and in this way voltage spikes are avoided and you can save correspondingly structural weight for elements of the structure and for the whole structure.

According to the invention, this problem is solved. because the rear section of the fuselage of an airplane according to the preamble of claim 1 of the patent presents the following features:

to)

The rear section of the fuselage consists of a section front of the SA steering wheel and by a rear section of the lift stabilizer HA in the direction of flight (F), which are rigidly connected to each other;

b)

The SA steering wheel section comprises extreme frames with lift structure, which reinforces, respectively, in the plane of the frame, which consists of reinforcement braces (HS horizontal braces, VS vertical braces, braces diagonals DS), which are aligned almost orthogonally with with respect to the others;

C)

Nodal points of the braces of reinforcement of an extreme frame are joined with nodal points of the other extreme frame through RS space braces inclined in relation to the direction of flight.

The essential advantage of the configuration according to the invention of the load bearing structure consists of the distribution of the main loads applied throughout interior trajectories, optimal of the load, which are carried out at through the corresponding configuration of the internal structure from the rear section of the fuselage. The configuration put here in Close-up of the SA steering wheel section with ace reinforcement support structures and the binding of the frames extreme through space braces provides a homogeneous distribution of the load and tension, respectively. In this case, the development of the trajectory of the approximately orthogonal configured load leads to nodes of load with a maximum of rigidity with a minimum use of material.

Through the invention, the charges are absorbed and distributed along face paths internal, of optimal weight, to achieve a weight in this way structure minimum. The internal charges, which result because external loads, applied through the connections of the stabilizer, are absorbed and diverted through the interior construction, are minimized through the constructive configuration according to the invention of the structure interior, which avoids voltage spikes. In one way correspondingly, construction weight is saved in this way to the structural elements and the general structure.

A particularly advantageous configuration of a rear section of fuselage according to the invention, which achieves especially orthogonal loading paths, consists in that the extreme frames of the steering wheel section present in their upper area, respectively, a contour in shape of V formed by upper reinforcement braces, configuring the ends of the arms of the V with other reinforcement braces a pair of upper load nodes, on which the steering wheel hardware. This is effective, since in the connection area of the frame is mainly present a thrust load

With the same objective of achieving trajectories of orthogonal loading serves another advantageous configuration of the invention, which is that in the extreme front frame of the steering helm section SA, the other braces of reinforcement, which start from the upper load nodes, are vertical straps, which extend V-shaped down on nodal points in the plane of the frame and flow essentially in the center of the plane of the frame in a node central.

The configuration according to the invention of a cross section of the fuselage with other configurations advantageous is described with the help of embodiments, which They are represented in the drawings.

In the drawings:

Figure 1 shows a transport plane with a rear section of the fuselage, in which the lifting stabilizer and steering wheel.

Figure 2 shows an enlarged representation of the rear section of the fuselage of figure 1, being shown for stabilizers only support drawers of the steering wheel 90 and the stabilizer support drawer  elevation 70.

Figure 3 shows a middle section schematic longitudinal through the rear section of the fuselage according to figure 2 with the division in a section of the rudder of SA direction a section of the lifting stabilizer HA.

Figure 4 shows on the left side of the there is a schematic top plan view and part right of the figure a schematic longitudinal middle section a through the steering wheel section SA.

Figure 5 shows an oblique image of the structure of the steering rudder section according to the figure 4.

Figure 6 shows the top plan view against flight direction F over the extreme frame front of the steering wheel section SA.

Figure 7 shows an enlarged representation of a top fragment of the view according to figure 6, and

Figure 8 shows a top plan view of the flight direction F on the rear end frame of the steering wheel section SA.

The transport aircraft 1 represented in the Figure 1 in the oblique view presented for fixing the lifting stabilizer 7 and steering wheel 9 a section rear of the fuselage 2 configured for this purpose according to the invention.

Figure 2 shows the rear section of the fuselage 2 in the oblique image in exterior view, in which a outer lining is designated with 8, which comprises the SA steering wheel section and stabilizer section of HA elevation. From the steering wheel 9 only the drawer is shown of steering wheel holder 90, which is fixed on hardware connection 21, 41. Also of the lifting stabilizer 7 is shows only the stabilizer support drawer elevation 70, whose axis of rotation 76 is indicated with dots and strokes.  The direction of vision in Figure 2 inside the rear section of fuselage 2 against flight direction F also shows the front end frame 20 of the section of the SA steering wheel and its rear end frame 40 as well as intermediate arranged frames, not shown in detail.

The central longitudinal view, represented in Figure 3, from the rear section of the fuselage 2 shows its distribution in the front section of the SA steering wheel and the rear section of the HA stabilizer, which are attached rigidly with each other. The steering helm section SA comprises an extreme front frame 20 and an extreme frame rear 40. The two extreme frames are rigidly joined each other through RS space braces and a support element 30. In the upper area of the extreme frames 20, 40 are fixed rudder hardware 21, 41. The symbols of KN reference designate nodal points of reinforcement braces of the extreme frame 40, which are joined with nodal points of the other extreme frame 40 through RS space braces inclined with respect to flight direction F. Other details about the configuration of the steering wheel section is deduced from figures 4 to 8. The support element 30 is rests on top load nodes 24, 44 (see Figure 6 or Figure 8) and in other upper load nodes KN of the frame extreme 20, 40.

On the top floor view and the view Sideways shown adjacent to the steering wheel section SA in figure 4, the arrangement of the braces is shown RS spacers for the rigid connection of the front end frame 20 and the rear end frame 40. The RS space braces they run between the nodes located near the central plane of the plane in front frame 20 and the nodes located in the exterior in the rear frame 40. The RS space braces are arranged at different height and symmetrically to the middle plane longitudinal longitudinal of the rear section of the fuselage 2, being designated in Figure 4 the upper space braces with RSo and the lower space braces with RSu. The inclination of RS space braces with respect to the longitudinal median plane vertical of the rear section of the fuselage 2 should not be in this case greater than 60º, so that the relationship of the components of the force, which can be transmitted in the longitudinal direction between the extreme frames 20, 40, with Regarding the general strength. The support element 30 is configured with diagonal braces 32 inclined in space. In addition, it has a base plate 34 that runs essentially horizontally.

In the oblique image, shown in Figure 5, of the structure of the steering wheel section SA can be recognize the connection points of the space braces upper RSo and lower space braces RSu in nodes loading of both the structure of support of the frame extreme front 20 as well as in load nodes of the frame rear end 40. The outer covering 8 (figure 2), involved in the distribution and transmission of the forces that appear and fixed in the inner support structure, it has also omitted in this representation (figure 2). The structure of lift of the front end frame 20 is represented in the view according to figure 6. The extreme frame 20 has a V-shaped contour in its upper area through braces of upper reinforcement 23r and 231, which are essentially directed orthogonal to each other and are in a node of load, in which the upper ends of the arms of the V configure with other reinforcement braces 25r, 251, aligned essentially vertical, top loading nodes 24, in which steering wheel fittings 21r, 21l are fixed. The following conduction of the vertical straps 25 down is carried out in such a way that load paths are obtained almost orthogonal and ends at a central node ZKN, from which other diagonal braces are guided, again almost orthogonal to the sides of the extreme frame.

For the uniform advantageous application of support forces, to absorb from the steering wheel drawer, in the side stabilizer section of the rear section of the fuselage, steering wheel hardware 21 (figure 6) not only they are provided, as is known per se, with joining ribs that they are placed vertically down, but they also have angular stumps 22, which are positioned obliquely down, adapted for fixing on upper reinforcement straps 23 (V-shaped connection). Through this configuration, it they can apply the extremely large forces that come from rudder moment in a way especially favorable in the structure of the steering wheel section of the rear section of the fuselage.

From the expanded representation of the upper area of the extreme frame 20 with the drawer connection from the steering wheel 90 (figure 7) a function is obtained additional of the steering wheel 21 hardware, which consists of that in said fittings transverse connection eyelets are arranged 92 for fastening transverse force flanges 19 of the drawer of the steering wheel 90. The cross force flanges 91 are fixed with the other ends, respectively, in a central rib 95 of the steering wheel drawer 90.

The view shown in figure 8 of the frame rear end 40 of the steering wheel section SA of the rear section of the fuselage corresponds to the view of the frame front end 20 according to figure 6. The upper area of this rear end frame 40 is configured in a manner similar to the extreme frame 20, that is, an outline is set in V-shape through reinforcing braces 43r, 43l. Also they Steering wheel hardware 41r, 41l are configured in one similar way to the steering wheel hardware for the extreme front frame 20. The support structure, formed by reinforcement braces, from the extreme frame 40 se difference in the support structure of the extreme frame 20 because you have to keep a central zone ZB free of the frame extreme for the passage of activation elements for the lifting stabilizer 7. Maintaining the principle of at least approximately orthogonal load paths, it extend the vertical struts VS, which start from the nodes of top load 44, down to the nodal points marginal 48, in which HS horizontal braces end and diagonal braces DS.

The marginal nodal points 48 are found in the upper third of the transverse surface of the rib.

The steering wheel hardware 41l They have upward connection eyelets for fixing bolts of the steering rudder and angular stumps 42l are configured V-shaped open down, adapted for fixing on the upper reinforcing braces 43l, VS.

Both extreme frames 20, 40 are reinforced usually with push walls. However, the braces of reinforcement within the frame are adapted to the development orthogonal of the main paths in such a way that considerably reduces the push request of the thrust walls In this way, they can be partially suppressed the thrust walls can either be made with thicknesses of reduced wall

The right material for the configuration of the rudder section structure is, in general, light metal; however, weight savings can be achieved large also using fiber reinforced materials for Topology of the structure proposed here.

Claims (14)

1. Rear section of the essentially barrel-shaped fuselage, configured as a load bearing structure, adapted for fixing the lifting stabilizer and steering wheel, of an airplane with frames that extend in transverse planes, stringers that extend in the longitudinal direction and an outer covering and with a transverse opening, which extends essentially horizontal, for the passage of the lifting stabilizer, characterized by the following characteristics:

to)

The rear section of the fuselage (2) consists of a section front of the rudder (SA) and by a rear section of the lift stabilizer (HA) in the direction of flight (F), which they are rigidly connected to each other;

b)

The steering wheel section (SA) includes extreme frames (20, 40) with support structure, which reinforces, respectively, in the plane of the frame, which is constituted by reinforcement braces (HS horizontal braces, braces vertical VS, diagonal braces DS), which are almost aligned orthogonally with respect to each other;

C)

Nodal points (KN, ZKN) of the reinforcement braces (HS, VS, DS) of an extreme frame (20) are joined with nodal points (KN) of the other extreme frame (40) through inclined space braces (RS) in relation to The flight direction.

2. Rear section of the fuselage of an aircraft according to claim 1, characterized in that the extreme frames (20, 40) of the steering rudder section (SA) have, in their upper area, respectively, a V-shaped contour formed by upper reinforcement straps (23r, I), configuring the ends of the arms of the V with other reinforcement straps a pair of upper loading nodes (24, 44), in which the steering rudder hardware (21r , 21l, 41r, 41l). 3. Rear fuselage section according to claim 2, characterized in that in the front end frame (20) of the steering rudder section (SA), the other reinforcement braces, which start from the upper loading nodes (24), they are vertical braces (25), which extend V-shaped downwards on nodal points (KN) in the plane of the frame and essentially flow into the center of the plane of the frame in a central node (ZKN). 4. Rear section of the fuselage according to claims 1 to 3, characterized in that in the rear end frame (40) the other reinforcing braces, which start from the upper loading nodes (44), are vertical braces (VS), which are they extend to marginal nodal points (48), formed by other diagonal braces (DS) and horizontal braces (HS), the marginal nodal points (48) being arranged in the upper third of the cross-sectional surface area of the frame. 5. Rear section of the fuselage according to claims 1 to 4, characterized in that the reinforcing braces (VS, DS, HS) of the support structure, which reinforces the rear end frame (40), are guided in such a way that it is maintained Free a central area (ZB) of the cross section of the extreme frame for the passage of activation elements for the lifting stabilizer (7). 6. Rear section of the fuselage according to claims 1 to 5, characterized in that the steering wheel fittings (21, 41), as known per se, have upward connection eyelets for steering wheel fixing bolts (9) and V-shaped angular stumps (22, 42) are configured open downwards, adapted for fixing on the upper reinforcing straps (23, 43). 7. Rear section of the fuselage according to claims 1 to 6, characterized in that the steering rudder fittings (21, 41) have transverse connection eyelets (92) for fixing transverse force flanges (91 R, 91 L) of the steering wheel drawer (90). 8. Rear fuselage section according to claims 1 to 7, characterized in that between the end frames (20, 40) of the steering rudder section (SA) a support element (30) is inserted which transmits force preferably in direction flight (F), which is supported by the upper load node (24, 44) and optionally on other load nodes (KN) of the extreme frames (20, 40). 9. Rear fuselage section according to claim 8, characterized in that the support element (30) is configured with diagonal braces (32) inclined in the space. 10. Rear fuselage section according to claims 8 or 9, characterized in that the support element (30) has a base plate (34) that extends essentially horizontally. 11. Rear fuselage section according to claims 1 to 10, characterized in that the space braces (RS) are arranged at different height and symmetrically to the vertical longitudinal median plane of the rear section of the fuselage (2). 12. Rear section of the fuselage according to claims 1 to 11, characterized in that the space braces (RS) extend between nodes arranged in the vicinity of the middle plane of the plane in the front frame (20) and nodes arranged outside in the frame rear (40). 13. Rear fuselage section according to one or more of claims 1 to 12, characterized in that the thrust stiffness of the extreme frames (20, 40) is achieved in large part through the optimal, almost orthogonal arrangement of the shoulder straps. reinforcement along the optimal trajectories of the load, so that the thrust walls need smaller wall thicknesses or can be partially or totally suppressed. 14. Rear section of the fuselage according to one or more of claims 1 to 13, characterized in that the entire structure or individual elements consist of light metal or fiber reinforced material.