A dual-nozzle flying engine overlapping cover structure

Abstract

The present application belongs to the field of aviation engines, and particularly relates to a dual-nozzle flying engine overlapping outer cover structure, wherein the dual-nozzle flying engine overlapping outer cover structure mainly includes an outer shell and an inner shell in the shape of an arc sheet, the front and rear ends of the outer shell are serrated, the inner shell is located on the inner side of the outer shell, and has a partially overlapping overlapping area with the outer shell, the rear end of the outer shell overlaps the front end of the outer adjustment sheet and has a gap to avoid motion interference, and at the same time forms an airflow channel for the exchange between the engine compartment and the external flow. When the nozzle state is adjusted and changed, the flying engine overlapping outer cover always maintains a good overlapping relationship with the tail cover and the outer adjustment sheet, ensuring a good rectifying effect of the flying engine overlapping outer cover and meeting the requirements of the aircraft forward and engine rearward stealth.

Description

Technical Field

[0001] The present application belongs to the field of aero-engines, and in particular relates to a dual-nozzle flying engine overlap cover structure. Background Art

[0002] The overlapping outer cover structure of the military aviation engine is a component that connects the engine and the rear fuselage of the aircraft. It is a fairing structure that connects the outer adjustment plate of the engine nozzle with the tail cover of the aircraft. It is an important component system for realizing the integration of the engine and the rear fuselage of the aircraft. It is exposed outside the aircraft and engine body and should also have a stealth function.

[0003] The existing overlapping outer cover structure scheme of the aircraft engine is mainly based on the elastic sheet scheme of the compression contact type. Taking the conventional axisymmetric nozzle scheme as an example, the overlapping outer cover structure scheme of the aircraft engine is mainly composed of a support ring structure and an elastic sheet. The support ring is fixed to the barrel casing mounting seat through a support rod, and the elastic sheet is fixedly installed on the support ring. When the aircraft and the engine are assembled, the elastic sheet is pressed and contacted with the aircraft tail cover through elastic deformation. The stealth measure of the elastic sheet is mainly to use a stealth coating.

[0004] At present, the elastic sheet structure scheme of the axisymmetric nozzle pressing contact type in China has the following disadvantages:

[0005] (1) Reliability issues: In order to meet the air volume required for engine starting, the elastic sheet of the compression contact type is slotted. The elastic sheet is subject to the external flow field and elastic compression preload, and the slotted area is prone to large deformation and stress concentration, resulting in cracks.

[0006] (2) Reliability and weight gain of stealth coating: The elastic sheet is prone to large deformation and collision with adjacent components. In addition, due to the influence of vibration and thermal stress, the adhesion of the stealth coating will be greatly affected. The circumferential area of ​​the elastic sheet is large, and the stealth coating increases its weight.

[0007] At present, there is no dual-nozzle aircraft engine overlapping outer cover in China. If an elastic ring and a tail cover are used for overlapping, there will be overlapping steps, which does not meet the requirements of the aircraft engine integrated design and is not conducive to the stealth of the aircraft rear body. The elastic ring has a large area, and if a stealth coating is used, it will further increase the weight. Summary of the invention

[0008] In order to solve the above problems, the present application provides a dual nozzle flying engine overlapping outer cover structure: a dual nozzle flying engine overlapping outer cover structure, wherein the overlapping outer cover structure is overlapped between the outer adjustment plate and the tail cover, and the dual nozzle flying engine overlapping outer cover structure mainly includes an outer shell body and an inner shell body in the shape of an arc sheet, the front and rear ends of the outer shell body are serrated, the inner shell body is located on the inner side of the outer shell body, and has a partial overlapping overlap area with the outer shell body, there is a step between the two due to the thickness, and the two side ends of the outer shell body and the inner shell body are straight formed by bending The outer shell is fixedly connected to the two side walls of the nozzle through the fixed mounting edge; the tail cover is a part of the rear fuselage of the aircraft, and its tail end is serrated, and the trimming angle and number are consistent with the serrations at the front end of the outer shell. The tail of the tail cover is close to and overlaps the outer wall of the front end of the inner shell, and meshes with the serrations at the front end of the outer shell without a gap, and the tail cover and the outer surface of the outer shell have a smooth transition; the rear end of the outer shell overlaps the front end of the outer adjustment piece and has a gap to avoid motion interference, while forming an airflow channel for the exchange between the engine compartment and the external flow. When the nozzle state is adjusted, the overlapping outer cover of the flying engine always maintains a good overlapping relationship with the tail cover and the outer adjustment piece, ensuring a good rectifying effect of the overlapping outer cover of the flying engine and meeting the requirements of the aircraft forward and engine rearward stealth.

[0009] The specific scheme of the present application is as follows: the dual nozzle flying engine overlap outer cover structure is overlapped between the outer adjustment piece and the tail cover; the outer adjustment piece is located at the inner side of the rear end of the tail cover, and a gap is set between the outer adjustment piece and the tail cover;

[0010] The dual-element nozzle flying engine overlapped outer cover structure comprises an outer shell of an outer layer and an inner shell of an inner layer, the front end and the rear end of the outer shell are both serrated, and the serrated shape of the front end of the outer shell is butted with the serrated shape of the rear end of the tail cover; there is a step between the inner shell and the outer shell due to the thickness, and the two side ends of the outer shell and the inner shell are bent to form a straight fixed installation edge, and the outer shell is fixedly connected to the two side walls of the nozzle through the fixed installation edge;

[0011] The tail cover is a part of the rear fuselage of the aircraft, and its tail end is serrated. The angle and number of the serrations are consistent with the serrations at the front end of the outer shell. The tail of the tail cover overlaps the outer wall of the front end of the inner shell, and meshes with the serrations at the front end of the outer shell without a gap. The tail cover and the outer surface of the outer shell have a smooth transition. This can effectively reduce the resistance of the rear body of the aircraft's tail cover and reduce the step surface between the tail cover and the outer adjustment plate. In addition, both axial ends of the outer shell are serrated, and the front end and the tail cover are serrated accordingly, which can reduce the stealth problem caused by the connection between the flat surfaces and improve the stealth effect.

[0012] The front end of the inner housing extends forward and overlaps with the inner side surface of the tail cone cover. The two circumferential side ends of the outer housing have fixed mounting edges formed by bending. The outer housing is fixedly mounted to the two side walls of the nozzle through the fixed mounting edges. The cooperation of the overlap between the front end of the inner housing and the inner side surface of the tail cone cover, the meshing of the front end of the outer housing with the serrations of the tail cone cover, and the fixed mounting of the outer housing to the two side walls of the nozzle through the fixed mounting edges can constrain the dual-nozzle engine lap outer cover structure at multiple angles, achieving firm and stable assembly, and eliminating the need for traditional elastic sheet installation, resulting in a long-lasting and stable structure.

[0013] Preferably, an arc-shaped strip support reinforcement ring is installed inside the inner housing. The support reinforcement ring is arranged circumferentially along the inner housing and can provide the strength of the inner housing itself.

[0014] Preferably, the cross-section of the support reinforcement ring is in a "ji" shape, including a flat section in the middle and leg edges on both sides. The leg edges on both sides are in contact with the surface of the inner housing and are fixedly connected to the outer housing and the inner housing by welding or riveting. A ring cavity is formed between the support reinforcement ring and the surface of the inner housing. Multiple circumferentially distributed cushion cylinders are provided in the ring cavity. One end of the cushion cylinder is welded to the flat section, and the other end is installed in the corresponding mounting holes of the outer housing and the inner housing through the provided limit bosses. Screws or bolts fix the support reinforcement ring to the nozzle through the cushion cylinders. The "ji" shape structure of the support reinforcement ring can reduce the structural weight of the support reinforcement ring itself, while the cushion cylinders can achieve the installation strength of the support reinforcement ring, avoiding damage to the support reinforcement ring caused by the pre-tightening force of the screws when installing the support reinforcement ring with screws.

[0015] Preferably, the material of the outer housing includes a radar-absorbing functional resin matrix composite material, and a protective resin for changing the appearance color is coated on the outer surface to improve the stealth function of the outer housing.

[0016] Preferably, the front end of the inner housing is an inwardly curved surface for guiding the assembly during installation with the tail cone cover.

[0017] Preferably, the fixed mounting edge has a housing hole with a large aperture, and a housing threaded hole with a small aperture is located at the center of the housing hole;

[0018] A mounting seat is provided at the connection between the fixed mounting edge of the outer housing and the side wall. The mounting seat has a mounting seat hole corresponding to the position of the housing hole. An annular limit round platform is provided on the outer circle of the mounting seat hole. The limit round platform is placed in the housing hole, and a screw passes through the housing threaded hole and is connected to the mounting seat hole and the side wall.

[0019] Preferably, in the axial direction, the inner shell body is located as a whole at the front end of the outer adjustment plate. The inner shell body, the support reinforcement ring and the outer shell body form a step surface due to their different axial positions and heights. Together with the gap formed by the outer shell body and the outer adjustment plate, an S-shaped gas channel can be formed, which can achieve the outflow of gas and the stealth effect at the same time.

[0020] Preferably, the rear end of the outer shell and the outer adjustment sheet at the same axial position have curved surfaces with the same curvature, and the outer shell and the outer adjustment sheet have a gap formed by a radius difference.

[0021] Preferably, the inner diameter of the support reinforcement ring is smaller than the outer diameter of the outer adjustment plate, which can effectively block the gap formed by the radius difference between the outer shell and the outer adjustment plate, thereby improving the stealth effect.

[0022] Advantages of this application include:

[0023] (1) The overlapping outer cover of the flying engine implements the integrated design concept of the flying engine, adopts a double-layer design, single-layer overlap and zigzag docking method;

[0024] (2) A gap is left between the overlapping outer cover of the flight engine and the outer adjustment plate to avoid motion interference, and at the same time form an airflow channel for the exchange between the engine compartment and the external flow, reducing the pressure load on the overlapping outer cover of the flight engine and the outer adjustment plate; the air intake slit is eliminated to avoid stress concentration and cracks, and at the same time the airflow flows smoothly, reducing the rear body resistance of the aircraft and improving the stealth effect;

[0025] (3) The structure of the flight engine overlap cover adopts a "J"-shaped support reinforcement ring to ensure support and installation, while blocking radar waves entering through the gap between the flight engine overlap cover and the outer adjustment plate;

[0026] (4) The outer layer structure of the overlapping cover of the flying engine adopts a wave-absorbing resin-based composite material to solve the problem of coating weight increase and improve stealth performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the installation of the overlapping outer cover structure of the dual nozzle flying engine;

[0028] Figure 2 is a schematic diagram of the outer side of the shell;

[0029] Figure 3 is a schematic diagram of the inside of the shell;

[0030] Figure 4 This is a cross-sectional view of the Feifa overlapped outer cover structure

[0031] Figure 5 is a schematic diagram of the support reinforcement ring;

[0032] Figure 6It is a schematic diagram of the inner side of the installation relationship between the flying engine overlap cover structure and the outer adjustment plate;

[0033] Among them, 1-outer shell, 2-support reinforcement ring, 3-gasket, 4-mounting seat, 5-inner shell, 8-tail cover, 9-outer adjustment plate, 10-side wall. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the implementation of this application will be described in more detail in combination with the drawings in the implementation of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and cannot be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in combination with the drawings.

[0035] The present application provides a dual nozzle flying engine overlapping outer cover structure: the dual nozzle flying engine overlapping outer cover structure is overlapped between the outer adjustment piece 9 and the tail cover 8; the outer adjustment piece 9 is located at the inner side of the rear end of the tail cover 8, and a gap is set between the outer adjustment piece 9 and the tail cover 8;

[0036] The dual nozzle flying lapped outer cover structure comprises an outer shell 1 of an outer layer and an inner shell 5 of an inner layer. Figure 1 As shown, the front and rear ends of the outer shell 1 are both serrated, and the serrated modification of the front end of the outer shell 1 is connected with the serrated modification of the rear end of the tail cover 8; there is a step between the inner shell 5 and the outer shell 1 due to the thickness, such as Figure 2 As shown, both side ends of the outer shell 1 and the inner shell 5 are bent to form straight fixed mounting edges, and the outer shell 1 is fixedly connected to the two side walls 10 of the nozzle through the fixed mounting edges;

[0037] The tail cover 8 is a part of the rear fuselage of the aircraft, and its tail end is serrated, and the angle and number of the serrations are consistent with the serrations at the front end of the outer shell 1. The tail of the tail cover 8 overlaps the outer wall of the front end of the inner shell 5, and meshes with the serrations at the front end of the outer shell 1 without a gap. The tail cover 8 and the outer surface of the outer shell 1 have a smooth transition; it can effectively reduce the rear body resistance of the aircraft tail cover 8 and reduce the step surface between the tail cover 8 and the outer adjustment plate 9. In addition, both axial ends of the outer shell 1 are serrated, and the front end and the tail cover 8 are serrated accordingly, which can reduce the stealth problem caused by the connection between the flat surfaces and improve the stealth effect.

[0038] The front end of the inner housing 5 extends forward and lapped with the inner side surface of the tail cone 8. The two circumferential side ends of the outer housing 1 have fixedly installed edges formed by bending. The outer housing 1 is fixedly installed with the two side walls 10 of the nozzle through the fixedly installed edges. The cooperation of the lap joint between the front end of the inner housing 5 and the inner side surface of the tail cone 8, the meshing of the serrations between the front end of the outer housing 1 and the tail cone 8, and the fixed installation of the outer housing 1 with the two side walls 10 of the nozzle through the fixedly installed edges can constrain the dual-nozzle aircraft engine lap joint outer cover structure at multiple angles, realizing firm and stable assembly, and without the need to rely on traditional elastic sheet installation, with a long service life and stability.

[0039] Preferably, an arc-shaped strip-shaped support strengthening ring 2 is installed inside the inner housing 5. The support strengthening ring 2 is arranged along the circumference of the inner housing 5, and the support strengthening ring 2 can provide the strength of the inner housing 5 itself.

[0040] Preferably, as Figures 3 to 5 shown, the cross-section of the support strengthening ring 2 is in a "several" shape, including a flat section in the middle and leg edges on both sides. The leg edges on both sides are in contact with the surface of the inner housing 5 and are fixedly connected to the outer housing 1 and the inner housing 5 by welding or riveting. A ring cavity is formed between the support strengthening ring 2 and the surface of the inner housing 5. A plurality of circumferentially distributed cushion cylinders 3 are arranged in the ring cavity. One end of the cushion cylinder 3 is welded to the flat section, and the other end is installed in the corresponding mounting holes of the outer housing 1 and the inner housing 5 through the provided limit bosses. Screws or bolts fixedly connect the support strengthening ring 2 with the nozzle through the cushion cylinders 3. The "several" shape structure of the support strengthening ring 2 can reduce the structural weight of the support strengthening ring 2 itself, and at the same time, the cushion cylinders 3 can realize the installation strength of the support strengthening ring 2, avoiding damage to the support strengthening ring 2 caused by the pre-tightening force of the screws when installing the support strengthening ring 2 with screws.

[0041] Preferably, the material of the outer housing 1 includes a wave-absorbing functional resin matrix composite material, and a protective resin for changing the appearance color is coated on the outer surface to improve the stealth function of the outer housing 1.

[0042] Preferably, the front end of the inner housing 5 is an inwardly curved surface for guiding the assembly when installing with the tail cone 8.

[0043] Preferably, the fixedly installed edge has a housing hole with a large aperture, and a housing threaded hole with a small aperture is at the center of the housing hole;

[0044] There is a mounting seat 4 at the connection between the fixedly installed edge of the outer housing 1 and the side wall 10. The mounting seat 4 has a mounting seat hole corresponding to the position of the housing hole. An annular limit round platform is provided on the outer circle of the mounting seat hole. The limit round platform is placed in the housing hole, and a screw passes through the housing threaded hole and is connected to the mounting seat hole and the side wall 10.

[0045] Preferably, in the axial direction, the inner shell 5 is located as a whole at the front end of the outer adjustment piece 9. The inner shell 5, the support reinforcement ring 2 and the outer shell form a step surface due to the different axial positions and heights. Together with the gap formed by the outer shell and the outer adjustment piece 9, an S-shaped gas channel can be formed, which can achieve the outflow of gas and the stealth effect at the same time.

[0046] Preferably, the rear end of the outer shell 1 and the outer adjustment sheet 9 at the same axial position have curved surfaces with the same curvature, and the outer shell 1 and the outer adjustment sheet 9 have a gap formed by a radius difference.

[0047] Preferably, the inner diameter of the support reinforcement ring 2 is smaller than the outer diameter of the outer adjustment piece 9, which can effectively block the gap formed by the radius difference between the outer shell 1 and the outer adjustment piece 9, thereby improving the stealth effect. Figure 6 shown.

[0048] The flight-engine overlap cover is set on the outer periphery of the dual nozzle, with a total of two sets, arranged on the upper and lower sides of the dual nozzle. The flight-engine overlap cover structure is a non-moving component; when the nozzle state is adjusted and changed, the flight-engine overlap cover always maintains a good overlap relationship with the tail cover 8 and the outer adjustment plate 9, ensuring the good rectification effect of the flight-engine overlap cover and meeting the requirements of the aircraft forward and engine rearward stealth, such as Figure 6 shown.

[0049] 1. The overlapping outer cover of the flying engine implements the integrated design concept of the flying engine, adopts double-layer design, single-layer overlapping and zigzag docking;

[0050] 2. A gap is left between the overlapping outer cover of the flight engine and the outer adjustment plate to avoid motion interference, and at the same time form an airflow channel for the exchange between the engine compartment and the external flow, reducing the pressure load on the overlapping outer cover of the flight engine and the outer adjustment plate; the air intake slit is eliminated to avoid stress concentration and cracks, and at the same time the airflow flows smoothly, reducing the rear body resistance of the aircraft and improving the stealth effect;

[0051] 3. The flying engine overlap cover structure adopts a "J"-shaped support reinforcement ring to ensure support and installation, while blocking the radar waves entering through the gap between the flying engine overlap cover and the outer adjustment plate;

[0052] 4. The outer layer structure of the Feifa overlapped cover adopts wave-absorbing functional resin-based composite materials to solve the problem of coating weight increase and improve stealth performance.

[0053] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A dual nozzle flying lap cover structure, characterized in that: The binary nozzle engine connection outer cover structure is connected between the outer adjusting vane (9) and the tail cover (8); the outer adjusting vane (9) is located inside the rear end of the tail cover (8), and there is a gap between the outer adjusting vane (9) and the tail cover (8). The binary nozzle engine connection outer cover structure includes an outer shell body (1) on the outer layer and an inner shell body (5) on the inner layer. The front end and the rear end of the outer shell body (1) are serrated and shaped. The serrated shape at the front end of the outer shell body (1) is对接 with the serrated shape at the rear end of the tail cover (8). The front end of the inner shell body (5) extends forward and搭接 with the inner side surface of the tail cover (8). Both side ends of the outer shell body (1) in the circumferential direction have fixed installation edges formed by bending. The outer shell body (1) is fixedly installed with two side walls (10) of the nozzle through the fixed installation edges. An arc-shaped support and strengthening ring (2) is installed inside the inner shell body (5), and the support and strengthening ring (2) is arranged along the circumference of the inner shell body (5). The whole inner shell body (5) is located at the front end of the outer adjusting vane (9). The rear end of the outer shell body (1) has a curved surface with the same curvature as the outer adjusting vane (9) at the same axial position, and there is a gap formed by the radius difference between the outer shell body (1) and the outer adjusting vane (9). The inner diameter of the support and strengthening ring (2) is smaller than the outer diameter of the outer adjusting vane (9).

2. The dual nozzle flying lap cover structure according to claim 1, characterized in that: The cross-section of the support and strengthening ring (2) is in a "several" shape, including a flat section in the middle and leg edges on both sides. The leg edges on both sides contact the surface of the inner shell body (5) and are fixedly connected to the outer shell body (1) and the inner shell body (5) by welding or riveting. A ring cavity is formed between the support and strengthening ring (2) and the surface of the inner shell body (5). A plurality of circumferentially distributed cushion cylinders (3) are arranged in the ring cavity. One end of the cushion cylinder (3) is welded to the flat section, and the other end is installed in the corresponding installation holes of the outer shell body (1) and the inner shell body (5) through the limiting bosses. Screws or bolts connect the support and strengthening ring (2) with the nozzle through the cushion cylinders (3).

3. The dual nozzle flying lap cover structure according to claim 1, characterized in that: The material of the outer shell body (1) includes a wave-absorbing functional resin matrix composite material, and a protective resin for changing the appearance color is coated on the outer surface.

4. The dual nozzle flying jet overlap cover structure according to claim 1, characterized in that: The front end of the inner shell body (5) is an inward arc-shaped surface for guiding the assembly when installing with the tail cover (8).

5. The binary nozzle engine connection outer cover structure according to claim 1, characterized in that The fixed installation edge has a large-aperture housing hole, and the center of the housing hole has a small-aperture housing threaded hole. There is an installation seat (4) at the connection between the fixed installation edge of the outer shell body (1) and the side wall (10). The installation seat (4) has an installation seat hole corresponding to the position of the housing hole. The outer ring of the installation seat hole has an annular limiting round platform, and the limiting round platform is placed in the housing hole. Screws pass through the housing threaded hole and the installation seat hole to connect with the side wall (10).

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