RU2783796C1 - Method for manufacturing hull of high-speed aircraft - Google Patents

Abstract

FIELD: aviation.

SUBSTANCE: invention relates to aviation and concerns the structures of the components of the hulls of high-speed aircraft (AC) (outer shells or panels of aerodynamic surfaces) made of a composite material based on carbon fabric and silicon carbide. Manufacturing of a component part of the body includes the manufacture of carbon-carbon blanks for the outer shell or panel of the aerodynamic surface with the elements of the power set, followed by assembly using fasteners. In this case, carbon-carbon blanks undergo mechanical processing, mutual adjustment and assembly using fasteners. Fasteners are made from carbon-carbon blanks. Moreover, the fasteners form screw-nut pairs, where the heads of the screws that come out on the surface of the outer bypass are made with protruding parts to ensure assembly, including tightening the screw-nut connections with a torque. After that, the protruding parts are cut off flush with the outer circumference and the assembled structure is silicified.

EFFECT: manufacturing of structures of AC body components operating in high-speed oxidizing flows, increasing manufacturability of manufacturing and assembly, and increasing the reliability of the structure.

5 cl, 4 dwg

Description

The claimed technical solution relates to the field of aircraft (LA), namely to the structures of the components of the hulls of high-speed aircraft - outer shells or panels of aerodynamic surfaces made of a composite material based on carbon fabric and silicon carbide, as well as to methods for their manufacture.

A known method (see, for example, RF patent No. 2058964) for obtaining a composite material based on carbon fiber and silicon carbide, including the manufacture and siliconization of a carbon-carbon blank.

There is also known a method for manufacturing a wing-type aircraft assembly according to the patent of the Russian Federation No. in matrices with extended through slots with bridges in the walls by attracting the frames with technological loops to the jumpers, followed by flashing them with fibers through the extended through slots of the matrices, after which the technological loops are cut, the frames are removed from the matrices with extended through slots, impregnated with a binder, installed in the forming dies and polymerization is performed, then the frameworks are removed from the forming dies, they are machined and the unit is assembled with fastening of the skins and elements of the power set with screws.

The method for manufacturing a wing-type aircraft assembly according to RF patent No. 2385258 has the following disadvantages:

- the propeller material is not specified, which does not allow us to draw a conclusion about the possible range of application of such a design in high-speed aircraft;

- no technical solution is presented that allows high-temperature processing of the structure assembled on the above fastener;

- this method does not describe the technical feasibility of manufacturing structures of aircraft body components operating in high-speed oxidizing flows at temperatures of 1500°C or more.

This method is taken as the closest analogue.

The technical problem to be solved by the claimed technical solution is:

- fabrication of structures of aircraft body components, the material of which makes it possible to operate in high-speed oxidizing flows at temperatures of 1500°C and more;

- increasing manufacturability and assembly;

- increasing the reliability of the design.

The task is achieved by the fact that the method of manufacturing an integral part of the body of a high-speed aircraft (LA), from a composite material based on carbon fabric and silicon carbide, consists in the manufacture of carbon-carbon blanks for the outer shell or panel of the aerodynamic surface with elements of the power set and siliconization of carbon - carbon blanks, while the carbon-carbon blanks are machined, mutually adjusted and assembled using fasteners made of carbon-carbon blanks, while the fasteners form screw-nut pairs, the screw heads facing the surface of the outer contour are made with protrusions to ensure assembly, including tightening the torque of screw-nut connections, and then cutting off the protrusions flush with the outer contour and siliconizing the assembled structure.

In all elements of the power set, forming closed cavities, drainage holes are made to eliminate the possibility of pressure increase in these cavities during high-temperature heating during siliconization, as well as during the flight of the aircraft.

The locking of the screw-nut connections is ensured by monolithization along the contact surfaces of the parts in the process of high-temperature heating during siliconizing.

The assembly is carried out on a slipway, while the preliminary assembly is carried out using technological fasteners, and after assembly and mutual adjustment of the parts, the technological fasteners are dismantled in a sequence that ensures the manufacturability of the assembly, with the replacement of these fasteners with carbon-carbon fasteners.

Technological fasteners are selected with a smaller diameter than carbon-carbon fasteners and the corresponding holes for technological fasteners are made of a smaller diameter, and during assembly, technological fasteners are sequentially removed and holes for carbon-carbon fasteners are drilled with a possible displacement from the axis of the original hole within the difference between the diameters of two holes and followed by the installation of carbon-carbon fasteners.

The proposed technical solution is illustrated by drawings.

In FIG. 1 is a view of the component part of the hull, which shows the shell 1, a set of frames 2 and the fastening of the frames to the shell with nuts 3 and screws 4, in which the protruding part is cut off after torque tightening. Position 5 shows a screw with a protruding part to ensure assembly and tightening with a torque, after which the protruding part is cut off.

In FIG. 2 shows a section A-A along one of the frames 2, which shows the fastening of this frame to the shell 1 along a closed perimeter with nuts 3 and screws 4, the protruding parts of which have already been cut off.

In FIG. Figure 3 shows a view from callout B, which shows on an enlarged scale the fastening of the frame 2 to the shell 1 with a nut 3 and a screw 4, in which the protruding part is cut off.

In FIG. Figure 4 shows a view along the callout B, which shows the fastening of the frame 2 to the shell 1 with a nut 3 and a screw 5, in which the protruding part has not yet been cut off.

The assembly method is as follows.

The carbon-carbon blanks of the hull component parts, including the carbon-carbon blanks of the fasteners, are machined to be included in the assembly.

The assembly takes place in a slipway, where the parts are mutually adjusted using additional machining, and after that the carbon-carbon parts are assembled using technological fasteners in the form of metal screws and nuts with a smaller diameter thread. Preliminary assembly in a jig of a component part of the body on a metal fastener allows for mutual adjustment of parts, increasing productivity and manufacturability of the assembly. In addition, the use of fasteners of a smaller diameter allows, if necessary, the final holes for carbon-carbon fasteners to be offset within the difference between the diameters of the preliminary and final holes in order to ensure the necessary alignment of the hole package in the mating parts.

During assembly, drainage holes are made in all elements of the power set that form closed cavities to eliminate the possibility of pressure increase in these cavities during high-temperature heating during siliconization, as well as during the flight of the aircraft. Thus, additional load on the power elements of the housing component is eliminated, and, thereby, the reliability of the structure is increased.

Once the pre-assembly is completed, the process fasteners are replaced with carbon-carbon fasteners in a sequence that maintains the accuracy and quality of the assembly. After tightening the screw-nut connections with a torque, the screw heads protruding beyond the outer contour are cut flush with the outer contour.

The final assembled part of the hull is siliconized. The locking of the screw-nut connections is ensured by monolithization along the contact surfaces of the parts in the process of high-temperature heating during siliconizing.

The proposed method has been tested under production conditions, and the hull components manufactured by this method have successfully passed laboratory bench and flight design tests as part of an aircraft.

The use of the proposed technical solution will allow:

- to manufacture structures of aircraft body components operating in high-speed oxidizing flows at temperatures of 1500°C or more;

- improve manufacturability and assembly;

- increase the reliability of the design.

Claims (5)

1. A method for manufacturing an integral part of the body of a high-speed aircraft from a composite material based on carbon fabric and silicon carbide, including the manufacture of carbon-carbon blanks for the outer shell or airfoil panel with elements of the power set, followed by assembly using fasteners, characterized in that carbon - carbon blanks are machined, mutually adjusted and assembled using fasteners made of carbon-carbon blanks, while the fasteners form screw-nut pairs, the screw heads facing the surface of the outer contour are made with protruding parts to ensure assembly, including torque tightening of the screw-nut connections, and then cutting off the protruding parts flush with the outer contour and siliconizing the assembled structure. 2. A method for manufacturing a component part of a high-speed aircraft body according to claim 1, characterized in that all elements of the power set forming closed cavities have drainage holes to eliminate the possibility of pressure increase in these cavities during high-temperature heating during siliconizing. 3. A method for manufacturing an integral part of the body of a high-speed aircraft according to claim 1, characterized in that the locking of the screw-nut connections is ensured by monolithization along the contact surfaces of the parts during high-temperature heating during siliconizing. 4. A method for manufacturing an integral part of the body of a high-speed aircraft according to claim 1, characterized in that the assembly is carried out on a slipway, while the preliminary assembly is performed using technological fasteners, and after assembly and mutual adjustment of the parts, the technological fasteners are dismantled in a sequence that ensures the manufacturability of the assembly , with the replacement of this fastener with a carbon-carbon fastener. 5. A method for manufacturing an integral part of the body of a high-speed aircraft according to claim 4, characterized in that the technological fasteners are selected with a smaller diameter than the carbon-carbon fasteners, and the corresponding holes for the technological fasteners are made of a smaller diameter, and during assembly, the technological fasteners are sequentially removed and produced reaming holes for carbon-carbon fasteners with a possible offset from the axis of the original hole within the difference between the diameters of the two holes and with the subsequent installation of carbon-carbon fasteners.

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