Integral manufacturing method for rear fuselage structure of airplane

Abstract

The invention belongs to the technical field of aircraft rear fuselage structure manufacturing, and particularly relates to an aircraft rear fuselage structure integral manufacturing method which comprises the steps that firstly, a rear fuselage integral structure is designed; 2, the rear fuselage structure is divided into multiple sections, specifically, the frame beam integral piece configuration serves as a basic segmentation unit, the rear fuselage structure is divided into multiple sections, and the number of segments of the rear fuselage structure is the same as the number of frames in a rear fuselage force bearing component; selecting a segmented interface of a rear fuselage structure, wherein the segmented interface is located at a part with relatively low stress level between two adjacent frames; thirdly, the rear fuselage structures of all the sections are manufactured through forge pieces or additional materials; and 4, sequentially connecting all the sections of the rear fuselage structure by adopting a forming connection mode of electron beam fuse forming and conformal annealing to obtain an integral structure of the rear fuselage.

Description

Technical Field

[0001] The present application belongs to the technical field of aircraft rear fuselage structure manufacturing, and specifically relates to an integral manufacturing method of an aircraft rear fuselage structure. Background Art

[0002] At present, the rear fuselage structure of an aircraft is usually designed to be composed of a reinforced frame transverse member and a fuselage beam longitudinal member, which are mechanically connected by corner boxes, profiles, etc. This type of structure has a large number of parts, requires a large number of tooling and dies for processing and assembly, has a large structure weight, and has many weak links such as fastener holes, resulting in a short fatigue life of the aircraft rear fuselage structure.

[0003] This application is proposed in view of the above-mentioned technical defects. Summary of the invention

[0004] The purpose of the present application is to provide a method for integrally manufacturing an aircraft rear fuselage structure, so as to overcome or alleviate at least one of the known technical deficiencies.

[0005] The technical solution of this application is:

[0006] A method for integrally manufacturing an aircraft rear fuselage structure, comprising:

[0007] Step 1: Design the overall structure of the rear fuselage;

[0008] Step 2: Divide the rear fuselage structure into multiple sections:

[0009] The rear fuselage structure is divided into multiple sections with the frame beam integral member configuration as the basic section unit, and the number of sections of the rear fuselage structure is the same as the number of frames in the rear fuselage load-bearing components;

[0010] Select the rear fuselage structure segment interface, which is located between two adjacent frames at a relatively low stress level;

[0011] Step 3: Use forgings or additive manufacturing to manufacture each section of the rear fuselage structure;

[0012] Step 4: Use electron beam fuse forming + conformal annealing to connect the various sections of the rear fuselage structure in sequence to obtain the overall structure of the rear fuselage.

[0013] According to at least one embodiment of the present application, in the above-mentioned aircraft rear fuselage structure integral manufacturing method, in step 1, the rear fuselage integral structure is designed according to the arrangement of the rear fuselage load-bearing components and the ambient temperature conditions;

[0014] The overall structure of the rear fuselage is designed to be made of high-temperature resistant titanium alloy material.

[0015] According to at least one embodiment of the present application, in the above-mentioned method for integrally manufacturing the aircraft rear fuselage structure, in step 2, a location with a relatively low stress level between two adjacent frames is determined by finite element analysis.

[0016] According to at least one embodiment of the present application, in the above-mentioned method for integrally manufacturing the rear fuselage structure of an aircraft, in step 3, the dimensions of the remaining parts of each section of the rear fuselage structure, except for the formed connection area, are machined to the final dimensions;

[0017] The margin for the connection area of ​​the rear fuselage structure of each section is reserved with a range of 20mm on each side.

[0018] According to at least one embodiment of the present application, in the above-mentioned method for manufacturing the entire rear fuselage structure of an aircraft, in step 4, each section of the rear fuselage structure is connected by forming with an electron beam fuse, and during the forming process, the connection area is scanned by a fast electron beam multiple times;

[0019] After the various sections of the rear fuselage structure are connected, the connecting area is machined to the final size to complete the manufacturing of the entire rear fuselage structure.

[0020] This application has at least the following beneficial technical effects:

[0021] The beneficial effects of the above method are:

[0022] Provided is a method for manufacturing an integral aircraft rear fuselage structure, which adopts segmented manufacturing + electron beam fuse forming connection + conformal annealing to obtain an integrated rear fuselage integral structure, so that the number of parts is sharply reduced from more than 20 to 1, thereby achieving a substantial weight reduction of the structure, and the assembly process and tooling are greatly simplified, which can shorten the structural processing and manufacturing cycle. In addition, the number of weak links such as fastener holes is greatly reduced, and the structural load-bearing efficiency and fatigue life are greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram of an integral manufacturing method of an aircraft rear fuselage structure provided by an embodiment of the present application;

[0024] Figure 2 is a schematic diagram of the overall structure of the rear fuselage provided in an embodiment of the present application;

[0025] Figure 3 It is a schematic diagram of the finite element analysis results of the overall structure of the rear fuselage provided in an embodiment of the present application.

[0026] In order to better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. In addition, the drawings are only used for illustrative purposes and should not be construed as limitations on the present application. DETAILED DESCRIPTION

[0027] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present application will be described in further detail in detail and in detail with reference to the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present application, which are only used to explain the present application, not to limit the present application. It should be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, and other related parts can refer to the general design.

[0028] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application shall have the usual meanings understood by those of ordinary skill in the art to which this application belongs. The words used in the description of this application to indicate orientation are only used to indicate relative directions or positional relationships. When the absolute position of the described object changes, its relative positional relationship may also change accordingly. The word "include" used in the description of this application indicates that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, but does not exclude other elements or objects.

[0029] In addition, it should be noted that, unless otherwise clearly specified and limited, the words "installation", "connection" and similar terms used in the description of this application should be understood in a broad sense. For example, the connection can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Technical personnel in the field can understand its specific meaning in this application according to the specific circumstances.

[0030] Electron beam fuse deposition forming technology is an important branch of additive manufacturing technology. It has technical advantages such as high forming efficiency and low operating costs. Electron beam scanning can be used in the part forming process to achieve stress relief annealing, that is, conformal annealing, which can effectively control the deformation of parts. Therefore, it can be used to connect multiple large and complex frame beam integral parts together to achieve a lightweight overall structure with fewer connections.

[0031] Based on the above embodiments of the present application, a method for manufacturing an aircraft rear fuselage structure as a whole is provided, such as Figure 1As shown, the larger aircraft rear fuselage structure is segmented according to the number of frame beams according to the arrangement of the rear fuselage load-bearing components, and each segment is a smaller independently manufacturable frame beam integral part, which is then connected by electron beam fuse deposition forming technology. During the connection process, form-following annealing is performed to control the deformation of the parts. That is, the excess in the forming connection area is removed by mechanical processing by adopting the method of segmented manufacturing + electron beam fuse forming connection + form-following annealing to obtain the overall structure of the rear fuselage, thereby realizing the design / manufacturing of the overall rear fuselage structure with high quality and high precision. No connecting corner boxes, corner pieces or other connecting parts and fasteners are required, which greatly reduces the fatigue weak parts and structural weight of the mechanical connection area, and can ensure the strength, rigidity and precision of the overall components of the rear fuselage. It is a typical lightweight and long-life structure.

[0032] Step 1: Design the overall structure of the rear fuselage.

[0033] According to the arrangement of the rear fuselage load-bearing components and the ambient temperature conditions, the overall structure of the rear fuselage is designed, including the traditional frame, beams and other load-bearing parts, such as Figure 2 shown.

[0034] Since the engine is installed at the rear of the aircraft, which is a high-temperature area, the overall structure of the rear fuselage is designed to be made of high-temperature resistant titanium alloy material.

[0035] Step 2: Divide the rear fuselage structure into multiple sections.

[0036] The rear fuselage structure is divided into multiple sections with the frame beam integral member configuration as the basic section unit. The number of sections of the rear fuselage structure is the same as the number of frames in the rear fuselage load-bearing components.

[0037] Considering that the load-bearing capacity and fatigue resistance of the electron beam forming connection area are generally weaker than those of the parent material, the rear fuselage structure segment interface, which is located at a position with a relatively low stress level between two adjacent frames, is selected as the connection part for electron beam fuse forming.

[0038] In a specific example, the finite element analysis results of the rear fuselage overall structure are as follows: Figure 3 As shown, the part with relatively low stress level is used as the segmented interface of the two-section rear fuselage structure.

[0039] Step 3: Use forgings or additive manufacturing to manufacture each section of the rear fuselage structure.

[0040] Except for the formed connection area, the remaining dimensions of the rear fuselage structure of each section are machined to the final size.

[0041] The margin in the connection area of ​​the rear fuselage structure of each section is reserved with a range of 20mm on each side, which will be removed by machining after the overall forming and connection.

[0042] Step 4: Use electron beam fuse forming + conformal annealing to connect the various sections of the rear fuselage structure in sequence to obtain the overall structure of the rear fuselage.

[0043] Electron beam fuse forming and connection are adopted for each section of the rear fuselage structure. During the forming process, the connection area is subjected to multiple rapid electron beam scans. This is a low-stress rapid forming method that can better control the deformation of each section of the rear fuselage structure, so that each section of the rear fuselage structure is added to the final size before forming and connection, and will not be deformed after forming and connection.

[0044] After the various sections of the rear fuselage structure are connected, the connecting area is machined to the final size to complete the manufacturing of the entire rear fuselage structure.

[0045] The overall manufacturing method of the aircraft rear fuselage structure disclosed in the above-mentioned embodiment eliminates the separation surfaces of the longitudinal and transverse components of the structure, adopts forgings or additive manufacturing to manufacture the integral parts of each section of the frame beam, and then adopts the forming connection method of electron beam fuse deposition forming + conformal annealing to connect the integral parts of each section of the frame beam to obtain an integrated rear fuselage overall structure. Compared with the rear fuselage structure designed, processed and assembled in the existing way, the number of parts is sharply reduced from more than 20 to 1, the number of weak links such as fastener holes is reduced by more than 30%, the assembly process and tooling are greatly simplified, the structure weight is reduced by more than 20%, and the structural efficiency is greatly improved.

[0046] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the scope of protection of the present application.

Claims

1. A method for integrally manufacturing an aircraft rear fuselage structure, characterized in that: include: Step 1: Design the overall structure of the rear fuselage; Step 2: Divide the rear fuselage structure into multiple sections: The rear fuselage structure is divided into multiple sections with the frame beam integral member configuration as the basic section unit, and the number of sections of the rear fuselage structure is the same as the number of frames in the rear fuselage load-bearing components; Select the rear fuselage structure segment interface, which is located between two adjacent frames at a relatively low stress level; Step 3: Use forgings or additive manufacturing to manufacture each section of the rear fuselage structure; Step 4: Use electron beam fuse forming + conformal annealing to connect the various sections of the rear fuselage structure in sequence to obtain the overall structure of the rear fuselage.

2. The method for integrally manufacturing the aircraft rear fuselage structure according to claim 1, characterized in that: In step 1, the overall structure of the rear fuselage is designed according to the arrangement of the rear fuselage load-bearing components and the ambient temperature conditions; The overall structure of the rear fuselage is designed to be made of high-temperature resistant titanium alloy material.

3. The method for integrally manufacturing the aircraft rear fuselage structure according to claim 1, characterized in that: In step 2, the location with relatively low stress level between two adjacent frames is determined by finite element analysis.

4. The method for integrally manufacturing the aircraft rear fuselage structure according to claim 1, characterized in that: In step 3, the dimensions of the rear fuselage structure of each section, except the formed connection area, are machined to the final size; The margin for the connection area of ​​the rear fuselage structure of each section is reserved with a range of 20mm on each side.

5. The method for integrally manufacturing the aircraft rear fuselage structure according to claim 1, characterized in that: In step 4, each section of the rear fuselage structure is connected by electron beam fuse forming, and during the forming process, the connection area is scanned by a fast electron beam multiple times; After the various sections of the rear fuselage structure are connected, the connecting area is machined to the final size to complete the manufacturing of the entire rear fuselage structure.

Images