Installation Bracket, Pneumatic Device, Nacelle and Installation Method of Pneumatic Device

Abstract

The present invention discloses a mounting bracket, a pneumatic device, a nacelle and a method for mounting a pneumatic device. The mounting bracket has a first outer skin mounting surface and a second outer skin mounting surface. A protruding portion is provided between them, and its surface is parallel to both the first outer skin mounting surface and the second outer skin mounting surface. The drop of the protruding portion relative to the first outer skin mounting surface is greater than or equal to the thickness of the outer skin of the air inlet duct to be installed, and the drop of the protruding portion relative to the second outer skin mounting surface is greater than or equal to the thickness of the outer skin of the fan cowl to be installed. By setting the protruding portion, the mounting bracket can repair and match its design margin, so as to meet the requirements of the pneumatic step difference, thereby well controlling the accuracy of the pneumatic profile step difference of the nacelle, reducing the pneumatic resistance of the engine, and improving the fuel efficiency of the engine. The mounting bracket has a simple structure and is easy to operate, and can be adjusted within a reasonable range acceptable for the pneumatic performance.

Description

Technical Field

[0001] The present invention relates to a mounting bracket, a pneumatic device, a nacelle and a method for mounting a pneumatic device. Background Art

[0002] The engine nacelle mainly plays a role in rectifying the external airflow of the engine. Taking wing-mounted engines as an example, the nacelle is set to reduce the impact of the engine's hoisting on the wing profile. At the same time, in terms of the external shape of the nacelle, there are high requirements for the external shape of the nacelle in terms of both the aerodynamic drag and the distortion coefficient of the engine. To reduce the aerodynamic drag, after weighing factors such as cost and industrial level, the surface accuracy and quality of the parts located on the aerodynamic surface are improved as much as possible during production and manufacturing. In terms of assembly, through reasonable design of the assembly jig and high assembly positioning accuracy, good aerodynamic smoothness is ensured after the components are assembled.

[0003] For the front-end component structure located on the windward side of the nacelle, such as the inlet duct and the fan cowl, there may be an aerodynamic step difference at the connection between the inlet duct and the fan cowl. The aerodynamic step difference is the step difference degree of the structural components on the aerodynamic surface at the separation surface. The aerodynamic step difference is an important parameter affecting the aerodynamic drag in the aerodynamic smoothness, so it is inevitable in the structural design, especially in the manufacturing and assembly processes. Therefore, in the upstream link of product generation, processing and manufacturing, that is, in the structural design, the adjustability of the components after assembly should be fully considered.

[0004] In the traditional structural design form of the aerodynamic separation surface, one is to use two "L"-shaped angle bars back-to-back and mechanically connect them to support the outer skin of the inlet duct and the outer skin of the fan cowl, and the other is to use a "T"-shaped flange bar and mechanically connect it to support the outer skin of the inlet duct and the outer skin of the fan cowl. Neither of the above two design configurations considers adjusting after assembly to perform structural compensation on the aerodynamic surface in the design stage. Therefore, the control of the aerodynamic surface step difference completely depends on the manufacturing and assembly accuracy and process level of the parts. For the large and complex assembly unit structure with multiple processes and multiple assembly passes, there will inevitably be situations such as out-of-tolerance of the aerodynamic surface, especially the reverse step difference in terms of aerodynamic performance, which is difficult for assembly control. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defect that there is no repairable aerodynamic step difference after the components are assembled in the prior art, and to provide a mounting bracket, a pneumatic device, a nacelle and a method for mounting a pneumatic device.

[0006] The present invention solves the above technical problem through the following technical solutions:

[0007] An installation bracket, the installation bracket having a first outer skin mounting surface and a second outer skin mounting surface, the installation bracket being provided with a protruding portion between the first outer skin mounting surface and the second outer skin mounting surface, the surface of the protruding portion being parallel to both the first outer skin mounting surface and the second outer skin mounting surface, the drop of the protruding portion relative to the first outer skin mounting surface being greater than or equal to the thickness of the outer skin of the intake duct to be installed, and the drop of the protruding portion relative to the second outer skin mounting surface being greater than or equal to the thickness of the outer skin of the fan cowl to be installed.

[0008] In this solution, adopting this structural method, when the outer skin of the intake duct and the outer skin of the fan cowl are closely arranged and connected together, there will be a step height between the outer skin of the intake duct and the outer skin of the fan cowl due to problems such as surface machining accuracy, that is, the outer skin of the intake duct and the outer skin of the fan cowl cannot be arranged on the same horizontal plane, so that the two cannot obtain good aerodynamic smoothness after assembly. Therefore, a structure with certain geometric features is provided between the outer skin of the intake duct and the outer skin of the fan cowl, that is, the above-mentioned installation bracket. The installation bracket is installed between the outer skin of the intake duct and the outer skin of the fan cowl, and a protruding portion is provided between the first outer skin mounting surface and the second outer skin mounting surface of the installation bracket, which can compensate for the step difference in the front and rear structures of the air flow direction at the separation surface, that is, the connection part, after the outer skin of the intake duct and the outer skin of the fan cowl are assembled. At the same time, a reference point with a high position accuracy is provided through the protruding portion of the installation bracket, so that when the outer skin of the intake duct and the outer skin of the fan cowl are installed relative to the installation bracket, by respectively aligning and installing with the protruding portion, the requirements of the aerodynamic step difference are met, and the situation of reverse step difference is completely avoided.

[0009] At the same time, since the protruding portion is formed on the installation bracket, its size is set in a structural form with design margin, that is, the drop of the protruding portion relative to the first outer skin mounting surface is greater than or equal to the thickness of the outer skin of the intake duct to be installed, and the drop of the protruding portion relative to the second outer skin mounting surface is greater than or equal to the thickness of the outer skin of the fan cowl to be installed. That is to say, when the installation bracket is installed between the outer skin of the intake duct and the outer skin of the fan cowl, while ensuring that the surface of the protruding portion is parallel to both the first outer skin mounting surface and the second outer skin mounting surface, the protruding portion on the installation bracket can be repaired and adjusted, so that the protruding portion has adjustability, and then the surface of the protruding portion meets the requirements of the aerodynamic step difference with the outer skin of the intake duct and the outer skin of the fan cowl, thereby well controlling the step difference accuracy of the nacelle aerodynamic shape, and being able to avoid the generation of reverse aerodynamic step difference, reducing the aerodynamic drag of the engine, and improving the fuel efficiency of the engine. Moreover, the installation bracket has a simple structure and convenient process operation, has good operability, can be adjusted within a reasonable range where the positive step difference of the aerodynamic surface is acceptable in terms of aerodynamic performance, and has good economy.

[0010] Preferably, the mounting bracket is an integrally formed structure, and the mounting bracket includes a first branch, a second branch, and a third branch. The first branch and the second branch are arranged in parallel, and the third branch extends away from the outer skin of the air inlet duct or the outer skin of the fan casing, and is perpendicular to the first branch or the second branch. The first branch and the second branch are symmetrically structured with respect to the third branch.

[0011] In this solution, by setting the mounting bracket as an integrally formed structure, it is convenient for the manufacturing process and simplifies the processing of the mounting bracket. The mounting bracket is divided into three branches. The first branch and the second branch are arranged in parallel and are both parallel to the surface of the protruding part described above. The first branch and the second branch are symmetrically arranged with respect to the third branch, that is, the protruding part is located between the first branch and the second branch. This structural form facilitates the connection of the outer skin of the air inlet duct and the outer skin of the fan casing in the prior art, and also facilitates the installation of the mounting bracket with the outer skin of the air inlet duct and the outer skin of the fan casing. At the same time, the third branch is perpendicular to the first branch or the second branch and extends away from the outer skin of the air inlet duct or the outer skin of the fan casing. With this structural setting of the third branch, it is convenient for the connection of the outer skin of the air inlet duct and the outer skin of the fan casing in the prior art, and also makes the connection of the mounting bracket, the outer skin of the air inlet duct, and the outer skin of the fan casing more compact, improving the utilization rate of space.

[0012] A pneumatic device, the pneumatic device includes the mounting bracket as described above.

[0013] In this solution, applying the mounting bracket to the pneumatic device makes it more convenient to adjust the pneumatic step difference at the separation surface after the outer skin of the air inlet duct and the outer skin of the fan casing are assembled, so that the protruding part of the mounting bracket, the outer skin of the air inlet duct, and the outer skin of the fan casing are on the pneumatic surface. Thus, it can well control the accuracy of the pneumatic shape step difference of the nacelle, avoid generating reverse pneumatic step difference, reduce the pneumatic resistance of the engine, and improve the fuel efficiency of the engine. Moreover, the structure of this mounting bracket is simple and the process operation is also simple, with good operability. It can be adjusted within a reasonable range where the positive step difference of the pneumatic surface is acceptable in terms of pneumatic performance, and has good economy.

[0014] Preferably, the pneumatic device includes an air inlet duct and a fan casing. The air inlet duct includes an outer skin of the air inlet duct, and the outer skin of the air inlet duct is covered on the first outer skin mounting surface. The fan casing includes an outer skin of the fan casing, and the outer skin of the fan casing is covered on the second outer skin mounting surface.

[0015] In this solution, adopting this structural form for the mounting bracket can facilitate the connection of the outer skin of the air inlet duct and the outer skin of the fan casing in the prior art, and also facilitate the installation of the mounting bracket with the outer skin of the air inlet duct and the outer skin of the fan casing.

[0016] Preferably, the mounting bracket is an integrally formed structure, and the mounting bracket includes a first branch, a second branch, and a third branch. The first branch and the second branch are arranged in parallel, and the third branch extends away from the outer skin of the intake duct or the outer skin of the fan cowl and is perpendicular to the first branch or the second branch. The first branch and the second branch are symmetrically structured with respect to the third branch.

[0017] In this solution, by setting the mounting bracket as an integrally formed structure, it is convenient for process manufacturing and simplifies the processing process of the mounting bracket. The mounting bracket is divided into three branches. The first branch and the second branch are arranged in parallel and are both parallel to the surface of the protruding part described above. The first branch and the second branch are symmetrically arranged with respect to the third branch, that is, the protruding part is located between the first branch and the second branch. This structural form facilitates the connection between the outer skin of the intake duct and the outer skin of the fan cowl in the prior art and also facilitates the installation of the mounting bracket with the outer skin of the intake duct and the outer skin of the fan cowl. At the same time, the third branch is perpendicular to the first branch or the second branch and extends away from the outer skin of the intake duct or the outer skin of the fan cowl. With this structural setting of the third branch, it is convenient for the connection between the outer skin of the intake duct and the outer skin of the fan cowl in the prior art and also makes the connection between the mounting bracket, the outer skin of the intake duct, and the outer skin of the fan cowl more compact, improving the utilization rate of space.

[0018] Preferably, the first branch forms the first outer skin mounting surface near the outer skin of the intake duct, and the second branch forms the second outer skin mounting surface near the outer skin of the fan cowl.

[0019] In this solution, the first branch of the mounting bracket is movably connected to the intake duct, and the second branch of the mounting bracket is movably connected to the fan cowl. That is, the first outer skin mounting surface on the first branch is movably connected to the outer skin of the intake duct on the intake duct, and the second outer skin mounting surface on the second branch is movably connected to the outer skin of the fan cowl on the fan cowl. Adopting this connection method facilitates the connection between the outer skin of the intake duct and the outer skin of the fan cowl in the prior art and also facilitates the installation of the mounting bracket with the outer skin of the intake duct and the outer skin of the fan cowl. At the same time, it also makes the connection between the mounting bracket, the outer skin of the intake duct, and the outer skin of the fan cowl more compact, improving the utilization rate of space.

[0020] Preferably, the outer skin of the intake duct includes a sacrificial layer, and the sacrificial layer is located inside the outer skin of the intake duct and is movably connected to the first outer skin mounting surface on the first branch.

[0021] In this solution, a sacrificial layer is provided at the outer skin of the air intake near the mounting bracket, that is, the sacrificial layer is located in the middle between the outer skin of the air intake and the first outer skin mounting surface on the first branch. The purpose of setting the sacrificial layer is as follows: When assembling the mounting bracket on the outer skin of the air intake, if the height difference between the outer skin of the air intake and the protruding part does not meet the requirements of the aerodynamic step difference, it is necessary to repair the sacrificial layer so that the outer skin of the air intake and the protruding part of the mounting bracket meet the requirements of the aerodynamic step difference. Compared with other repair methods for adjusting the protruding parts of the outer skin of the air intake and the mounting bracket, this repair method of repairing the sacrificial layer can ensure that the carbon fiber ply on the outer skin of the air intake is not damaged, ensuring the aerodynamic smoothness of the surface of the outer skin of the air intake and also ensuring the integrity of the outer skin of the air intake.

[0022] Preferably, the outer skin of the fan cowl includes an abrasion-proof strip, and the abrasion-proof strip is located inside the outer skin of the fan cowl and is in contact connection with the second outer skin mounting surface on the second branch.

[0023] In this solution, an abrasion-proof strip is provided at the outer skin of the fan cowl near the mounting bracket, that is, the abrasion-proof strip is located in the middle between the outer skin of the fan cowl and the second outer skin mounting surface on the second branch. The purpose of setting the abrasion-proof strip is as follows: When assembling the mounting bracket on the outer skin of the fan cowl, the abrasion-proof strip can prevent the outer skin of the fan cowl from wearing and damaging the second branch on the mounting bracket, ensuring the integrity of the mounting bracket.

[0024] Preferably, the air intake includes a rear bulkhead, and the rear bulkhead is located at the connection junction of the air intake and the fan cowl and is movably connected to the third branch.

[0025] In this solution, a rear bulkhead is provided on the air intake. The rear bulkhead is located at the connection of the air intake and the fan cowl, so that the rear bulkhead is movably connected to the third branch of the mounting bracket. By movably connecting the rear bulkhead with the mounting bracket, it is realized that the air intake and the fan cowl are supported and connected by the mounting bracket at the separation surface, that is, the connection junction, ensuring the compactness of the connection between the mounting bracket and the air intake and the rear bulkhead, and improving the utilization rate of space.

[0026] A nacelle, the nacelle includes the pneumatic device as described above.

[0027] In this solution, the pneumatic device is arranged on the nacelle. By this pneumatic device, it is realized that the nacelle meets the requirements of the aerodynamic step difference in the direction of the airflow, thereby well controlling the accuracy of the aerodynamic shape step difference of the nacelle, avoiding the generation of reverse aerodynamic step difference, reducing the aerodynamic drag of the engine, and improving the fuel efficiency of the engine.

[0028] A pneumatic device installation method, the pneumatic device installation method includes the mounting bracket as described above, and the specific installation steps are as follows:

[0029] S11. Connect the first outer skin mounting surface on the mounting bracket to contact the outer skin of the air intake passage, so that the elevation difference between the outer skin of the air intake passage and the protruding part meets the requirements of the aerodynamic step difference;

[0030] S12. Connect the second outer skin mounting surface on the mounting bracket to contact the outer skin of the fan cowl;

[0031] S13. Repair and fit the protruding part on the mounting bracket according to the installation position relationship between the mounting bracket and the outer skin of the fan cowl;

[0032] S14. Finally, make the three surfaces of the outer skin of the air intake passage, the protruding part and the outer skin of the fan cowl jointly form an aerodynamic surface.

[0033] In this solution, when the pneumatic device is installed in this way and the three surfaces of the protruding part of the mounting bracket, the outer skin of the air intake passage and the outer skin of the fan cowl jointly form an aerodynamic surface, this structural form of the mounting bracket can make the connection between the mounting bracket, the air intake passage and the fan cowl more compact, improve the space utilization rate, as well as the stability and reliability of the connection among the three.

[0034] Preferably, in step S11, the means to make the elevation difference between the outer skin of the air intake passage and the protruding part meet the requirements of the aerodynamic step difference include: using grinding and repairing the sacrificial layer or adding a gasket between the first outer skin mounting surface and the outer skin of the air intake passage.

[0035] In this solution, in order to make the elevation difference between the outer skin of the air intake passage and the protruding part of the mounting bracket meet the requirements of the aerodynamic step difference, two means can be taken: First, if the elevation height of the outer skin of the air intake passage is greater than the design margin of the protruding part, the sacrificial layer inside the outer skin of the air intake passage can be repaired and fitted until the outer skin of the air intake passage and the protruding part meet the requirements of the aerodynamic step difference; Second, if the elevation height of the outer skin of the air intake passage is lower than the design margin of the protruding part, a gasket can be added between the outer skin of the air intake passage and the first outer skin mounting surface until the outer skin of the air intake passage and the protruding part meet the requirements of the aerodynamic step difference.

[0036] Preferably, in step S11, the means to make the elevation difference between the outer skin of the air intake passage and the protruding part meet the requirements of the aerodynamic step difference include: using grinding and repairing the sacrificial layer or adding a gasket between the first outer skin mounting surface and the outer skin of the air intake passage.

[0037] In this solution, in order to make the height difference between the outer skin of the fan cowl and the protruding part of the mounting bracket meet the aerodynamic step difference requirement, two measures can be taken: First, if the height difference of the outer skin of the fan cowl is greater than the design allowance of the protruding part, the sacrificial layer inside the outer skin of the fan cowl can be repaired until the outer skin of the fan cowl and the protruding part meet the aerodynamic step difference requirement; Second, if the height difference of the outer skin of the fan cowl is lower than the design allowance of the protruding part, a gasket can be added between the outer skin of the fan cowl and the mounting surface of the second outer skin until the outer skin of the fan cowl and the protruding part meet the aerodynamic step difference requirement.

[0038] Preferably, the gasket is a liquid gasket or a peelable solid gasket.

[0039] Preferably, after step S11, it further includes sealing the connection between the mounting bracket and the outer skin of the intake duct by means of bonding.

[0040] In this solution, by using the bonding connection method at the connection between the mounting bracket and the outer skin of the intake duct, the contact area between the mounting bracket and the outer skin of the intake duct can be increased, making the connection between the mounting bracket and the outer skin of the intake duct more compact, stable and reliable.

[0041] The positive and progressive effects of the present invention are as follows: By providing a protruding part at the connection between the intake duct outer skin and the fan cowl outer skin of the mounting bracket, and the protruding part has a design allowance that can be repaired, so after the intake duct outer skin and the fan cowl outer skin are assembled, the step difference of the front and rear structures in the airflow direction at the separation surface, that is, the connection, can be compensated by repairing the design allowance, making the surfaces of the protruding part, the intake duct outer skin and the fan cowl outer skin lie on the aerodynamic surface, meeting the aerodynamic step difference requirement, thereby well controlling the aerodynamic contour step difference accuracy of the nacelle, improving the appearance quality at the structural joint, avoiding the generation of reverse aerodynamic step difference, reducing the aerodynamic drag of the engine, and improving the fuel efficiency of the engine. Moreover, the mounting bracket has a simple structure and simple process operation, has good operability, can be adjusted within a reasonable range where the positive step difference of the aerodynamic surface is acceptable in terms of aerodynamic performance, and has good economy. Description of the Drawings

[0042] Figure 1 It is a schematic diagram of the overall structure of the nacelle according to an embodiment of the present invention.

[0043] Figure 2 It is a schematic diagram of the structure at the connection between the intake duct and the fan cowl according to an embodiment of the present invention.

[0044] Figure 3 It is a schematic diagram of the structure of the mounting bracket according to an embodiment of the present invention.

[0045] Figure 4 Flow chart of the installation method of a pneumatic device according to an embodiment of the present invention.

[0046] Description of reference numerals;

[0047] Installation bracket 1

[0048] First outer skin mounting surface 11

[0049] Second outer skin mounting surface 12

[0050] First branch 13

[0051] Second branch 14

[0052] Third branch 15

[0053] Protrusion 16

[0054] Pneumatic device 2

[0055] Air intake duct 3

[0056] Air intake duct outer skin 31

[0057] Rear bulkhead 32

[0058] Fan cowl 4

[0059] Fan cowl outer skin 41

[0060] Abrasion-resistant strip 42

[0061] Nacelle 5 Detailed implementation manners

[0062] The present invention will be further described below by way of embodiments, but the present invention is not limited to the scope of the embodiments hereby.

[0063] For the nacelle 5 of the engine as Figure 1 shown, when the air intake duct outer skin 31 and the fan cowl outer skin 41 located on the front and rear sides are closely arranged and connected together, there will be a step height between the air intake duct outer skin 31 and the fan cowl outer skin 41 due to problems such as surface machining accuracy, that is, the air intake duct outer skin 31 and the fan cowl outer skin 41 cannot be arranged on the same horizontal plane, so that the two cannot obtain good aerodynamic smoothness after assembly.

[0064] Therefore, as Figures 1-3 shown, the present embodiment provides an installation bracket 1, which has a first outer skin mounting surface 11 and a second outer skin mounting surface 12. The first outer skin mounting surface 11 corresponds to the air intake duct outer skin 31, and the second outer skin mounting surface 12 corresponds to the fan cowl outer skin 41.

[0065] The mounting bracket 1 is provided with a protruding portion 16 between the first outer skin mounting surface 11 and the second outer skin mounting surface 12. The protruding portion 16 is a structure with certain geometric features. The surface of the protruding portion 16 is parallel to both the first outer skin mounting surface 11 and the second outer skin mounting surface 12 and has a design margin, that is, the drop of the protruding portion 16 relative to the first outer skin mounting surface 11 is greater than or equal to the thickness of the outer skin 31 of the intake duct to be installed, and the drop of the protruding portion 16 relative to the second outer skin mounting surface 12 is greater than or equal to the thickness of the outer skin 41 of the fan cowl to be installed. That is to say, when the mounting bracket 1 is installed between the outer skin 31 of the intake duct and the outer skin 41 of the fan cowl, while ensuring that the surface of the protruding portion 16 is parallel to both the first outer skin mounting surface 11 and the second outer skin mounting surface 12, the protruding portion 16 on the mounting bracket 1 can be trimmed to make the protruding portion 16 adjustable. Furthermore, the surface of the protruding portion 16 can meet the requirements of the aerodynamic step difference with the outer skin 31 of the intake duct and the outer skin 41 of the fan cowl, thereby well controlling the aerodynamic shape step difference accuracy of the nacelle 5, improving the appearance quality at the structural joint, avoiding the generation of reverse aerodynamic step difference, reducing the aerodynamic drag of the engine, and improving the fuel efficiency of the engine. Moreover, the structure of the mounting bracket 1 is simple, the process operation is also convenient, and it has good operability. It can be adjusted within a reasonable range where the forward step difference of the aerodynamic surface is acceptable in terms of aerodynamic performance, and has good economy.

[0066] The mounting bracket 1 can connect the outer skin 31 of the intake duct and the outer skin 41 of the fan cowl together by means of mechanical connection with fasteners and / or bonding. It can be determined according to specific circumstances. In this embodiment, the bonding connection method is adopted because bonding can increase the contact area between components, making the connection more stable and reliable. At the same time, the mounting bracket 1 is mostly made of metal materials, such as aluminum alloy or titanium alloy, etc., which reduces the difficulty of trimming the surface size of the protruding portion 16. When aligning the outer skin 31 of the intake duct and the outer skin 41 of the fan cowl relative to the surface of the protruding portion 16, more precise alignment can also be achieved by trimming the protruding portion 16, providing more adjustment means for controlling the aerodynamic shape step difference accuracy of the outer surface of the nacelle 5.

[0067] As Figure 3 shown, the mounting bracket 1 is an integrally formed structure, which is convenient for process manufacturing and simplifies the processing process of the mounting bracket 1. Among them, the mounting bracket 1 includes a first branch 13, a second branch 14 and a third branch 15.

[0068] Specifically, the first branch 13 and the second branch 14 are arranged in parallel. The first branch 13, the second branch 14 and the surface of the protrusion 16 are in the same plane. The first branch 13 and the second branch 14 are symmetrically structured with respect to the third branch 15, that is, the first branch 13 and the second branch 14 are located on both sides of the third branch 15, and the protrusion 16 is located between the first branch 13 and the second branch 14. This structural form facilitates the connection of the outer skin 31 of the air inlet duct and the outer skin 41 of the fan casing in the prior art, and also facilitates the installation of the mounting bracket 1 to the outer skin 31 of the air inlet duct and the outer skin 41 of the fan casing.

[0069] More specifically, the third branch 15 extends away from the outer skin 31 of the air inlet duct or the outer skin 41 of the fan casing, that is, it extends into the interiors of the air inlet duct 3 and the fan casing 4, and is perpendicular to the first branch 13 or the second branch 14. That is, the first branch 13, the second branch 14 and the third branch 15 together form a T shape. By setting it in this structural form, it facilitates the connection of the outer skin 31 of the air inlet duct and the outer skin 41 of the fan casing in the prior art, and also makes the connection of the mounting bracket 1, the outer skin 31 of the air inlet duct and the outer skin 41 of the fan casing more compact, improving the space utilization rate.

[0070] As Figure 2 shown, the above-mentioned mounting bracket 1 is placed in the pneumatic device 2. As described above: In the air inlet duct 3 and the fan casing 4, there may be a pneumatic step difference at the connection between the air inlet duct 3 and the fan casing 4. The pneumatic step difference is the step difference degree of the structural components on the pneumatic surface at the separation surface. The pneumatic step difference is an important parameter affecting the pneumatic resistance in the pneumatic smoothness, so it is inevitable in the structural design, especially in the manufacturing and assembly processes. Therefore, in the upstream link of product generation and manufacturing, that is, in the structural design, the adjustability of the components after assembly should be fully considered.

[0071] Therefore, applying the mounting bracket 1 to the pneumatic device 2 makes it more convenient to adjust the pneumatic step difference at the separation surface after the outer skin 31 of the air inlet duct and the outer skin 41 of the fan casing are assembled, so that the protrusion 16 of the mounting bracket 1, the outer skin 31 of the air inlet duct and the outer skin 41 of the fan casing are on the pneumatic surface. Thus, the pneumatic shape step difference accuracy of the nacelle 5 is well controlled, reverse pneumatic step difference is avoided, the pneumatic resistance of the engine is reduced, and the fuel efficiency of the engine is improved. Moreover, the mounting bracket 1 has a simple structure and simple process operation, has good operability, can be adjusted within a reasonable range where the positive step difference of the pneumatic surface is acceptable in terms of pneumatic performance, and has good economy.

[0072] As Figures 2-3As shown in the figure, the pneumatic device 2 includes an air inlet duct 3 and a fan cowl 4. The air inlet duct 3 includes an outer skin 31 of the air inlet duct, and the outer skin 31 of the air inlet duct is annularly arranged to form the air inlet duct 3. The fan cowl 4 includes an outer skin 41 of the fan cowl, and the outer skin 41 of the fan cowl is annularly arranged to form the fan cowl 4. The air inlet duct 3 and the fan cowl 4 are arranged and connected in sequence along their central axis directions, so a step difference is formed at the connection between the two. Therefore, the above-mentioned mounting bracket 1 is needed for compensation. Therefore, the outer skin 31 of the air inlet duct is laid on the first outer skin mounting surface 11, and the outer skin 41 of the fan cowl is laid on the second outer skin mounting surface 12, which is convenient for the connection between the outer skin 31 of the air inlet duct and the outer skin 41 of the fan cowl, and also convenient for the installation of the mounting bracket 1 with the outer skin 31 of the air inlet duct and the outer skin 41 of the fan cowl. At the same time, the outer skin 31 of the air inlet duct and the outer skin 41 of the fan cowl are composite materials, including but not limited to laminated plates and honeycomb core materials.

[0073] Among them, the mounting bracket 1 located between the outer skin 31 of the air inlet duct and the outer skin 41 of the fan cowl is also set as an integrally formed structure. The advantages of the mounting bracket 1 set in this structural form are as above and will not be elaborated here.

[0074] As Figure 2 shown in the figure, the first branch 13 of the mounting bracket 1 is connected to the outer skin 31 of the air inlet duct, and the second branch 14 is connected to the outer skin 41 of the fan cowl. Therefore, the first outer skin mounting surface 11 is arranged on the first branch 13 of the mounting bracket 1 near the outer skin 31 of the air inlet duct, and the second outer skin mounting surface 12 is arranged on the second branch 14 of the mounting bracket 1 near the outer skin 41 of the fan cowl. Adopting this connection method is convenient for the connection between the outer skin 31 of the air inlet duct and the outer skin 41 of the fan cowl in the prior art, and also convenient for the installation of the mounting bracket 1 with the outer skin 31 of the air inlet duct and the outer skin 41 of the fan cowl. At the same time, it also makes the connection between the mounting bracket 1, the outer skin 31 of the air inlet duct and the outer skin 41 of the fan cowl more compact, improving the space utilization rate.

[0075] Specifically, as Figure 2 shown in the figure, a sacrificial layer (not shown in the figure) is arranged on the surface of the outer skin 31 of the air inlet duct near the mounting bracket 1. The sacrificial layer is located in the middle between the outer skin 31 of the air inlet duct and the first outer skin mounting surface 11 on the first branch 13. The purpose of arranging the sacrificial layer is that when assembling the mounting bracket 1 on the outer skin 31 of the air inlet duct, if the step difference between the outer skin 31 of the air inlet duct and the protruding part 16 does not meet the requirement of the pneumatic step difference, it is necessary to repair the sacrificial layer to make the outer skin 31 of the air inlet duct and the protruding part 16 of the mounting bracket 1 meet the requirement of the pneumatic step difference. Compared with other repair methods for adjusting the protruding part 16 of the outer skin 31 of the air inlet duct and the mounting bracket 1, this repair method of repairing the sacrificial layer can ensure that the carbon fiber ply on the outer skin 31 of the air inlet duct is not damaged, ensuring the pneumatic smoothness of the surface of the outer skin 31 of the air inlet duct and also ensuring the integrity of the outer skin 31 of the air inlet duct.

[0076] Similarly, as Figure 2 shown, an anti-abrasion strip 42 is provided at the outer skin 41 of the fan shroud near the mounting bracket 1, that is, the anti-abrasion strip 42 is located in the middle of the outer skin 41 of the fan shroud and the second outer skin mounting surface 12 on the second branch 14. The material of the anti-abrasion strip 42 is but not limited to wear-resistant materials such as polytetrafluoroethylene PTFE and Teflon. The purpose of setting the anti-abrasion strip 42 is that when the mounting bracket 1 is assembled on the outer skin 41 of the fan shroud, the anti-abrasion strip 42 can prevent the outer skin 41 of the fan shroud from wearing and damaging the second branch 14 on the mounting bracket 1, ensuring the integrity of the mounting bracket 1.

[0077] As Figure 2 shown, a rear bulkhead 32 is provided on the intake duct 3. The rear bulkhead 32 is located at the connection between the intake duct 3 and the fan shroud 4, so that the rear bulkhead 32 is movably connected to the third branch 15 of the mounting bracket 1. Among them, the rear bulkhead 32 can be made of metal materials such as titanium alloy or aluminum alloy. At the same time, honeycomb sandwich composite materials can also be used.

[0078] By movably connecting the rear bulkhead 32 with the mounting bracket 1, the intake duct 3 and the fan shroud 4 are supported and connected by the mounting bracket 1 at the separation surface, that is, the connection, ensuring the compactness of the connection between the mounting bracket 1 and the intake duct 3 and the rear bulkhead 32, and improving the space utilization rate.

[0079] As Figures 1-2 shown, the above-mentioned pneumatic device 2 is placed in the nacelle 5. As mentioned above: The engine nacelle 5 mainly plays a role in rectifying the external air flow of the engine. Taking the wing-mounted type as an example, the nacelle 5 is set to reduce the influence of the engine hoisting on the wing profile. At the same time, in terms of the external shape of the nacelle 5, there are high requirements for the external shape of the nacelle 5 in terms of the aerodynamic drag and distortion coefficient of the engine. To reduce the aerodynamic drag, after weighing factors such as cost and industrial level in the production and manufacturing of parts, the surface accuracy and quality of the parts located on the aerodynamic surface are improved as much as possible. In terms of assembly, through reasonable design of the assembly jig and high assembly positioning accuracy, good aerodynamic smoothness is ensured after the parts are assembled. For the front-end component structure on the windward side of the nacelle 5, such as the intake duct 3 and the fan shroud 4, there may be an aerodynamic step difference at the connection between the intake duct 3 and the fan shroud 4. The aerodynamic step difference is the step difference degree of the structural components on the aerodynamic surface at the separation surface, that is, at the separation of the two component structures located on the aerodynamic surface, a convex platform step and a depression are formed along the air flow direction due to tolerance accumulation after assembly, and the aerodynamic step difference is an important parameter affecting the aerodynamic drag in the aerodynamic smoothness, so it is inevitable in the structural design, especially in the manufacturing and assembly processes. Therefore, in the upstream link of the product generation, processing and manufacturing, that is, in the structural design, the adjustability of the parts after assembly should be fully considered.

[0080] Therefore, when the nacelle 5 forms an aerodynamic step difference in the air flow direction, that is, the drop height of the outer skin 31 of the inlet duct is lower than the drop height of the outer skin 41 of the rear fan cowl, a certain resistance will be generated in the air flow direction, which poses a great potential hazard to the flight of the aircraft. At the same time, if the drop height of the outer skin 31 of the front section of the nacelle 5 is much greater than the drop height of the outer skin 41 of the rear fan cowl in the air flow direction, there will also be a great potential hazard to the flight of the aircraft.

[0081] Therefore, in this embodiment, the above-mentioned pneumatic device 2 is arranged in the nacelle 5, and the pneumatic device 2 can be used to meet the requirements of the aerodynamic step difference of the nacelle 5 in the air flow direction, so as to well control the accuracy of the aerodynamic shape step difference of the nacelle 5, avoid generating reverse aerodynamic step difference, reduce the aerodynamic resistance of the engine, and improve the fuel efficiency of the engine.

[0082] This embodiment also provides a method for installing a pneumatic device, as Figure 4 shown. This method for installing a pneumatic device is used to install the above-mentioned mounting bracket 1, and its installation steps can be generally summarized as follows:

[0083] S11. Connect the first outer skin mounting surface on the mounting bracket to contact the outer skin of the inlet duct, so that the drop between the outer skin of the inlet duct and the protruding part meets the requirements of the aerodynamic step difference;

[0084] S12. Connect the second outer skin mounting surface on the mounting bracket to contact the outer skin of the fan cowl;

[0085] S13. Repair and fit the protruding part on the mounting bracket according to the installation position relationship between the mounting bracket and the outer skin of the fan cowl;

[0086] S14. Finally, make the outer skin of the inlet duct, the protruding part and the outer skin of the fan cowl jointly form an aerodynamic surface. In this embodiment, the specific implementation manner of the method for installing a pneumatic device is as follows;

[0087] First, bring the first outer skin mounting surface 11 on the mounting bracket 1 into contact connection with the inlet duct outer skin 31 for pre-assembly. To ensure that the height difference between the inlet duct outer skin 31 and the protrusion 16 meets the aerodynamic step difference requirements, two implementation methods can be adopted: First, if the height difference of the inlet duct outer skin 31 is greater than the design allowance of the protrusion 16, the sacrificial layer inside the inlet duct outer skin 31 can be repaired until the inlet duct outer skin 31 and the protrusion 16 meet the aerodynamic step difference requirements; Second, if the height difference of the inlet duct outer skin 31 is lower than the design allowance of the protrusion 16, a gasket can be added between the inlet duct outer skin 31 and the first outer skin mounting surface 11 until the inlet duct outer skin 31 and the protrusion 16 meet the aerodynamic step difference requirements. Among them, the gasket in the second implementation method can be a liquid gasket or a peelable solid gasket, and the material of the peelable solid gasket includes but is not limited to stainless steel or polyester fiber. The specific implementation method can be selected according to the specific situation.

[0088] Secondly, seal the connection between the mounting bracket 1 and the inlet duct outer skin 31 by means of bonding, which can increase the contact area between the mounting bracket 1 and the inlet duct outer skin 31, making the connection between the mounting bracket 1 and the inlet duct outer skin 31 more compact, stable and reliable. At the same time, the inlet duct outer skin 31 and the protrusion 16 meet the aerodynamic step difference requirements.

[0089] Furthermore, bring the second outer skin mounting surface on the mounting bracket 1 into contact connection with the fan cowl outer skin 41. Usually, a process allowance of 2 mm - 5 mm is designed for the protrusion 16 on the mounting bracket 1. Under the condition of good dimensional accuracy of the assembly jig, try to reserve a process allowance of about 2 mm for the protrusion 16 as much as possible, so as to reduce the repair work during later assembly.

[0090] After assembling the mounting bracket 1 and the fan cowl outer skin 41, according to the outer convex or inner concave assembly position relationship between them, the height of the protrusion 16 on the mounting bracket 1 can be repaired locally or over a large area, so that the protrusion 16 and the outer surface of the fan cowl 4 meet the aerodynamic step difference requirements.

[0091] Such as Figure 2As shown, at the gap 6a between the outer skin 41 of the fan cover and the protruding portion 16, and at the gap 6b between the outer skin 31 of the air intake duct and the protruding portion 16, the above gaps can be sealed by applying and filling sealant, so that the connection between the mounting bracket 1 and the outer skin 41 of the fan cover is more compact, stable and reliable. At the same time, the outer skin 41 of the fan cover and the protruding portion 16 meet the requirements of the aerodynamic step difference. Compared with applying and filling sealant between the outer skin 31 of the air intake duct and the outer skin 41 of the fan cover in the prior art, in the present invention, by providing the protruding portion 16 on the mounting bracket 1 between the outer skin 31 of the air intake duct and the outer skin 41 of the fan cover, a basis for filling the sealant is provided, the stability of the filled sealant is improved, and the difficulty of filling the sealant can be reduced.

[0092] After all the steps are finally completed, the outer skin 31 of the air intake duct, the protruding portion 16 and the outer skin 41 of the fan cover can jointly form an aerodynamic surface.

[0093] Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that this is only an example, and the protection scope of the present invention is defined by the appended claims. Without departing from the principle and essence of the present invention, those skilled in the art can make various changes or modifications to these embodiments, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. An installation bracket, the installation bracket having a first outer skin mounting surface and a second outer skin mounting surface, characterized in that, The mounting bracket is provided with a protruding portion between the first outer skin mounting surface and the second outer skin mounting surface, and the surface of the protruding portion is parallel to both the first outer skin mounting surface and the second outer skin mounting surface. The drop of the protruding portion relative to the first outer skin mounting surface is greater than or equal to the thickness of the outer skin of the air inlet duct to be installed, and the drop of the protruding portion relative to the second outer skin mounting surface is greater than or equal to the thickness of the outer skin of the fan cowl to be installed.

2. The mounting bracket according to claim 1, characterized in that, The mounting bracket is of an integrally formed structure, and the mounting bracket includes a first branch, a second branch and a third branch. The first branch and the second branch are arranged in parallel. The third branch extends away from the outer skin of the air inlet duct or the outer skin of the fan cowl, and is perpendicular to the first branch or the second branch. The first branch and the second branch are symmetrically structured relative to the third branch.

3. A pneumatic device, characterized in that, The pneumatic device includes the mounting bracket as claimed in claim 1.

4. The pneumatic device according to claim 3, characterized in that, The pneumatic device includes an air inlet duct and a fan cowl. The air inlet duct includes an outer skin of the air inlet duct, and the outer skin of the air inlet duct is covered on the first outer skin mounting surface. The fan cowl includes an outer skin of the fan cowl, and the outer skin of the fan cowl is covered on the second outer skin mounting surface.

5. The pneumatic device according to claim 4, characterized in that, The mounting bracket is of an integrally formed structure, and the mounting bracket includes a first branch, a second branch and a third branch. The first branch and the second branch are arranged in parallel. The third branch extends away from the outer skin of the air inlet duct or the outer skin of the fan cowl, and is perpendicular to the first branch or the second branch. The first branch and the second branch are symmetrically structured relative to the third branch.

6. The pneumatic device according to claim 5, characterized in that, The first branch forms the first outer skin mounting surface near the outer skin of the air inlet duct, and the second branch forms the second outer skin mounting surface near the outer skin of the fan cowl.

7. The pneumatic device according to claim 6, characterized in that, The outer skin of the air inlet duct includes a sacrificial layer, and the sacrificial layer is located inside the outer skin of the air inlet duct and is movably connected to the first outer skin mounting surface on the first branch.

8. The pneumatic device according to claim 6, characterized in that, The outer skin of the fan cowl includes an anti-wear strip, and the anti-wear strip is located inside the outer skin of the fan cowl and is in contact connection with the second outer skin mounting surface on the second branch.

9. The pneumatic device according to claim 5, characterized in that, The air inlet duct includes a rear bulkhead, and the rear bulkhead is located at the connection junction of the air inlet duct and the fan cowl and is movably connected to the third branch.

10. A nacelle, characterized in that, The nacelle includes the pneumatic device as claimed in any one of claims 3-9.

11. A method for installing a pneumatic device, characterized in that, The installation method of the pneumatic device adopts the mounting bracket as claimed in claim 1, and the installation steps of the installation method of the pneumatic device are as follows: S11. Contact and connect the first outer skin mounting surface on the mounting bracket with the outer skin of the air inlet duct, so that the drop between the outer skin of the air inlet duct and the protruding portion meets the pneumatic step difference requirement. S12. Contact and connect the second outer skin mounting surface on the mounting bracket with the outer skin of the fan cowl. S13. Repair and fit the protruding portion on the mounting bracket according to the installation position relationship between the mounting bracket and the outer skin of the fan cowl. S14. Finally, make the outer skin of the air inlet duct, the protruding portion and the outer skin of the fan cowl jointly form a pneumatic surface.

12. The pneumatic device installation method according to claim 11, characterized in that, In step S11, the means to make the drop between the outer skin of the air inlet and the protruding part meet the aerodynamic step difference requirement include: using a sacrificial layer for grinding and fitting or adding a gasket between the first outer skin mounting surface and the outer skin of the air inlet.

13. The pneumatic device installation method according to claim 11, characterized in that, In step S12, the means to make the drop between the outer skin of the air inlet and the protruding part meet the aerodynamic step difference requirement include: using a sacrificial layer for grinding and fitting or adding a gasket between the first outer skin mounting surface and the outer skin of the air inlet.

14. The pneumatic device installation method according to any one of claims 12 or 13, characterized in that, The gasket is a liquid gasket or a peelable solid gasket.

15. The pneumatic device installation method according to claim 11, characterized in that, After step S11, it further includes sealing the connection between the mounting bracket and the outer skin of the air inlet by means of bonding.

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