Composite material engine air inlet channel structure and preparation method

Abstract

The invention belongs to the technical field of engines, and discloses a composite material engine air inlet channel structure and a preparation method, the structure comprises an air inlet channel first main body, an air inlet channel second main body, an air inlet channel main body partition plate and an air filter cover body; the first air inlet channel body is arranged on one side of the second air inlet channel body and fixedly connected with the second air inlet channel body through the medium-temperature adhesive film, one end of the air inlet channel body partition plate is fixedly connected with the first air inlet channel body, and the other end of the air inlet channel body partition plate is fixedly connected with the second air inlet channel body. The connector is connected with air filter equipment; a first air inlet channel is formed by the first air inlet channel body, the second air inlet channel body and the air inlet channel body partition plate and used for air inlet of the intercooler. The first air inlet channel body, the second air inlet channel body, the air inlet channel body partition plate and the air filter cover body form a second air inlet channel body which is used for air inlet of an engine, the structural weight is reduced through secondary glue joint, fastener connection is reduced, and compared with a liquid forming process, the structural mechanical property is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of engines and relates to an air intake duct structure of a composite material engine and a preparation method thereof. Background Art

[0002] In the field of modern aviation, the performance of aircraft engines is a key factor in ensuring flight safety, efficiency and the smooth completion of various flight missions. As the key channel for engine air intake, the design and performance of the aircraft nacelle air intake structure have a very important impact on the overall efficiency of the engine.

[0003] In order to ensure that the engine can obtain sufficient and uniform air flow in various complex working conditions (such as take-off, cruising, landing and other different flight stages, the engine has different speeds, power requirements, etc.), the intake duct must have a smooth and streamlined surface. From an aerodynamic point of view, a smooth surface can effectively reduce the airflow resistance when the air flows through the intake duct, avoid turbulence and other undesirable phenomena, and ensure that the air can enter the engine smoothly and stably.

[0004] In addition to the engine itself, the nacelle also houses many other important systems, such as the fuel system, hydraulic system, and electrical system. The layout of these systems needs to take into account multiple factors, such as space utilization, maintenance convenience, and safety. In the limited nacelle space, in order to meet the reasonable layout of each system and reserve appropriate space for the air intake, the air intake has to adopt this relatively special S-shaped structure, but the S-shaped structure is complex in appearance and is usually designed with a metal structure.

[0005] The following problems exist in the metal structure design: when conventional metal materials are used for manufacturing, it is difficult to obtain complete parts that meet the requirements through a one-time processing or molding process. The metal material can only be cut into multiple relatively simple combined parts, and then assembled into the final intake duct structure through mechanical connection (such as bolts, nuts, etc.) or welding. When the intake duct is working, various factors such as the operation of the engine and the impact of airflow during the flight of the aircraft will cause the intake duct to vibrate, reducing its reliability. Summary of the invention

[0006] The purpose of the present invention is to solve the shortcomings existing in the prior art and to propose a composite material engine intake duct structure and a preparation method. The first intake duct body, the second intake duct body, the intake duct body partition and the air filter cover are integrated into an integrated design and connected by a medium-temperature adhesive film. Under the premise of meeting the design requirements, the structural weight is reduced and the cost is reduced.

[0007] In order to achieve the above object, the present invention adopts the following technical solution: The present invention provides an air intake structure of a composite material engine, comprising a first air intake body, a second air intake body, an air intake body partition and an air filter cover; the first air intake body is arranged on one side of the second air intake body and is fixedly connected by a medium-temperature rubber film, one end of the air intake body partition is fixedly connected to the first air intake body, and the other end is fixedly connected to the second air intake body, and the air filter cover is arranged on a side of the air intake body partition away from the first air intake body, and is used to be connected to an air filter device.

[0008] Furthermore, the first intake duct body, the second intake duct body, and the intake duct body partition constitute an intake duct channel 1 for intercooler air intake; the first intake duct body, the second intake duct body, the intake duct body partition, and the air filter cover constitute an intake duct channel 2 for engine air intake.

[0009] Furthermore, the first main body of the air inlet duct has a C-shaped appearance and an L-shaped cross section.

[0010] Furthermore, a sunken area is arranged at the front end of the first main body of the air inlet duct, and a flanged flat plate area is arranged at the rear end.

[0011] Furthermore, a sunken area is provided at the front end of the second main body of the air inlet duct, and a flanged flat plate area is provided at the rear end.

[0012] Furthermore, a flanged flat plate area is provided at the rear end of the air inlet main body partition.

[0013] Furthermore, the first main body, the air intake duct second main body, the air intake duct main body partition, and the air filter cover are carbon fiber composite material laminates.

[0014] Furthermore, the second main body of the air inlet duct is a hyperbolic laminate.

[0015] A method for preparing a composite material engine intake duct structure is based on the above-mentioned composite material engine intake duct structure, comprising the following steps: a first intake duct body, a second intake duct body, an intake duct body partition, and an air filter cover are formed by heating and pressurizing in an autoclave; the first intake duct body and the second intake duct body are connected to form an intake duct; the intake duct is connected to the intake duct body partition to divide the intake duct into two air ducts.

[0016] Furthermore, the two air passages are air intake passage one and air intake passage two.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention discloses a composite material engine air intake structure, wherein a first air intake body, a second air intake body, an air intake body partition, and an air filter cover are made of composite materials, which can greatly reduce the weight of the structure under the same strength requirement. The composite materials are bonded twice, and the air intake structure with a complex shape can be formed at one time, thereby reducing the use of fasteners and the assembly workload, and improving the reliability and durability of the structure.

[0018] The present invention discloses a composite material engine air intake structure, which uses a medium-temperature adhesive film for connection, thereby increasing the structural rigidity and reducing the structural weight. In addition, the air intake structure can ensure excellent performance, greatly reduce the number of fasteners and the amount of assembly, reduce process difficulty, and have reliable quality and low cost.

[0019] The present invention discloses a composite material engine air intake structure, an air intake first body, an air intake second body, an air intake body partition and an air filter cover. Through a series of process steps such as paving and forming on a mold, vacuuming and heating and pressurizing in an autoclave, products with complex appearance and excellent mechanical properties can be manufactured. The products are widely used in the manufacture of parts with high requirements on structural strength and appearance accuracy in many fields such as aerospace, automobiles, and ships. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0021] Figure 1 This is a schematic structural diagram of a composite material engine intake structure of the present invention; Figure 2 An exploded view of a composite material engine intake structure of the present invention; Figure 3 A schematic diagram of the structure of an air intake duct in an embodiment of the present invention; Figure 4 Schematic diagram of the structure of the first main body of the air inlet in an embodiment of the present invention; Figure 5 is a schematic structural diagram of the second main body of the air inlet duct in an embodiment of the present invention; Figure 6 Schematic diagram of the structure of the air intake duct main body baffle in an embodiment of the present invention.

[0022] Reference numerals: 1-the first main body of the air intake duct; 2-the second main body of the air intake duct; 3-the main body partition of the air intake duct; 4-the air filter cover. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0024] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0025] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0026] Example 1 The present invention discloses a composite material engine air intake structure, comprising an air intake first body 1, an air intake second body 2, an air intake body partition 3 and an air filter cover 4, such as Figure 1 As shown in the figure, the first body 1, the second body 2 of the air intake duct, the air intake duct body partition 3 and the air filter cover 4 are carbon fiber composite laminates, which are bonded by medium-temperature secondary bonding. Compared with the traditional metal structure manufacturing process, medium-temperature secondary bonding does not require complex machining and welding processes. The composite material can be formed in the mold through a specific process, which reduces the steps and complexity of the manufacturing process and improves production efficiency. The secondary bonding enables the air intake duct to better disperse stress when it is subjected to various loads, improves the strength and stability of the structure, and makes the air intake surface more continuous and smooth, which is conducive to improving the aerodynamic performance of the air intake duct.

[0027] The first air inlet body 1 is arranged on one side of the second air inlet body 2 and is fixedly connected by a medium-temperature adhesive film. One end of the air inlet body partition 3 is fixedly connected to the first air inlet body 1 and the other end is fixedly connected to the second air inlet body 2. The air filter cover 4 is arranged on the side of the air inlet body partition 3 away from the first air inlet body 1 and is used to connect to the air filter device. In this embodiment, the fixed connection is fixed by using a medium-temperature adhesive film.

[0028] Specifically, Figure 2 As shown, the first intake duct body 1 and the second intake duct body 2 form an intake duct lip at the front, and form an intercooler connection frame with the intake duct body partition 3 at the rear. During high-speed flight, the lip can effectively introduce high-speed airflow into the intake duct while avoiding airflow separation and turbulence. The intercooler connection frame ensures a tight connection and good sealing between the intercooler and the intake duct, prevents air leakage and pressure loss, plays an important role in reducing the intake temperature, and improves the combustion efficiency and performance of the engine.

[0029] like Figure 4 As shown, the first main body 1 of the air intake duct is made of unidirectional tape, which is formed by manual laying. The unidirectional tape is a composite material composed of fibers arranged in a single direction and fixed by a resin matrix. It can withstand various stresses faced by the air intake duct during operation. In addition, the fiber direction of the unidirectional tape can be designed according to the stress conditions, so that the material has higher strength in a specific direction, thereby better meeting the mechanical requirements of the air intake duct structure.

[0030] Manual laying can better adapt to the shape changes of different parts and ensure that the unidirectional tape can fit tightly on the mold surface to obtain good molding quality. For areas with greater stress or special shapes, the number of unidirectional tape layers can be increased or the fiber direction can be adjusted to improve the strength and stability of the structure.

[0031] like Figure 5 As shown, the front end of the first main body 1 of the air intake duct is provided with a sunken area, and the rear end is provided with a flanged flat plate area. The front end of the second main body 2 of the air intake duct is provided with a sunken area, and the rear end is provided with a flanged flat plate area. The first main body 1 of the air intake duct and the second main body 2 of the air intake duct are connected to form the air intake duct. After gluing, the sunken area forms an air intake duct lip fitting area, which is fitted and connected with the engine cover body. The assembly is simple and the assembly workload is reduced. The flanged flat plate area forms the connection area of ​​the intercooler, and the end face opening is used to install the air filter equipment, which can filter impurities in the air entering the engine, such as dust, particulate matter, etc., to prevent these impurities from damaging the engine.

[0032] The upper and lower flanges of the air inlet main body partition 3 are used for gluing and connecting with the first air inlet body 1 and the second air inlet body 2. The upper and lower flanges increase the contact area of ​​the connection, making the gluing more firm and stable, and helping to disperse the impact and vibration of the airflow. The upper and lower flanges ensure that the connection parts will not easily loosen or separate, thereby maintaining the integrity of the overall structure of the airway.

[0033] like Figure 6 As shown, the rear portion of the intake duct main body partition 3 has a flat plate flange, which forms a connecting frame for the intercooler together with the flanged flat plate areas of the first intake duct body 1 and the second intake duct body 2. On the one hand, it ensures the stability of the intercooler during operation, and on the other hand, it is also beneficial to ensure the airflow sealing between the intercooler and the intake duct to prevent air leakage, thereby ensuring the normal working efficiency of the intercooler and the performance of the entire intake system.

[0034] The composite material engine intake duct structure integrates the engine intake and the intercooler intake into an assembly, which reduces the structural weight. The composite material structure design makes the manufacturing of parts with complex shapes simple, with good surface quality and good structural integrity. The first intake duct body 1 and the second intake duct body 2 constitute the intake duct, and the intake duct body partition 3 divides the intake duct into two air ducts.

[0035] Specifically, Figure 3 As shown, the first main body 1 of the air intake duct is responsible for guiding the air into the engine as part of the air intake duct, and the second main body 2 of the air intake duct and the first main body 1 of the air intake duct together constitute the outer wall of the air intake duct to ensure smooth and stable airflow. The air intake duct main body partition 3 divides the air intake duct into two independent air ducts, which are used for engine air intake and intercooler air intake respectively, which not only ensures that the engine and intercooler each obtain sufficient air flow, but also avoids airflow interference between the two. Through the integrated design, the integrity and stability of the structure are improved, and the durability and reliability of the parts are enhanced.

[0036] The two independent air ducts are intake channel one and intake channel two. Intake channel one is composed of an intake duct first body 1, an intake duct second body 2, and an intake duct body partition 3. Intake channel two is composed of an intake duct first body 1, an intake duct second body 2, an intake duct body partition 3, and an air filter cover 4.

[0037] Medium temperature film is a film material that plays a bonding role in a medium temperature range. Usually its curing temperature is between high temperature film and low temperature film, and this temperature range is generally around 80-120℃ (the specific temperature range varies depending on the different film formulas). It has good viscosity and fluidity, and can evenly spread and fill the tiny gaps on the bonding surface under appropriate temperature and pressure, thus forming a good bonding effect.

[0038] The curing temperature of high-temperature adhesive film is generally above 150°C. Although its bonding strength may be higher, it has strict requirements on equipment and process. When the bonding performance of medium-temperature adhesive film can meet most requirements, it does not require a high-temperature curing environment like high-temperature adhesive film, thereby reducing production costs and process difficulty. In addition, during the curing process, high-temperature adhesive film may have adverse effects on the bonded materials due to excessively high temperatures, while medium-temperature adhesive film is relatively mild.

[0039] The curing temperature of low-temperature adhesive film is relatively low, usually below 60°C. Its advantages are fast curing speed and wide adaptability to materials. However, the bonding strength and stability of low-temperature adhesive film after curing are often not as good as those of medium-temperature adhesive film. In the application scenario of aircraft air inlet, which has extremely high reliability requirements, medium-temperature adhesive film can provide a more durable and stable bonding effect, especially when subjected to long-term vibration and airflow impact.

[0040] In summary, the first air inlet body 1, the second air inlet body 2, the air inlet body partition 3 and the air filter cover 4 are made of carbon fiber composite laminates, which realize the integrated and lightweight design of the aircraft structure, meet the high surface quality requirements of the aircraft engine air inlet structure, and improve the durability and advancement of the air inlet structure. The medium-temperature adhesive film adopts secondary bonding, firstly solidifies and forms each part separately, which can be obtained by prepreg layering and then solidifying, and then uses adhesive film or glue to bond the already solidified parts together again under certain temperature, pressure and time conditions. Specifically, the first air inlet body 1 and the second air inlet body 2 are first manufactured, and then the two are bonded using the medium-temperature adhesive film.

[0041] For some structures that need to be repaired or replaced with some components, you only need to replace the damaged parts and re-glue them. The operation is simple, convenient and fast.

[0042] Example 2 A method for preparing a composite material engine intake duct structure comprises the following steps: an intake duct first body 1, an intake duct second body 2, an intake duct body partition 3, and an air filter cover 4 are formed by heating and pressurizing in an autoclave; the intake duct first body 1 and the intake duct second body 2 are connected to form an intake duct; the intake duct is connected to the intake duct body partition 3 to divide the intake duct into two air ducts.

[0043] Specifically: the first main body 1 of the air intake duct, the second main body 2 of the air intake duct, the main body partition 3 of the air intake duct, and the air filter cover 4 are fiber unidirectional laminate structures, using fiber unidirectional tape as the basic material, arranging high-strength fibers (such as carbon fiber, glass fiber, etc.) in a single direction, and fixed by impregnation with a resin matrix. The reasonable configuration of the fiber directions between different layers enables it to have good load-bearing capacity in multiple directions.

[0044] The fiber unidirectional tape is laid on the mold piece by piece according to the predetermined laying plan. During the laying process, it is necessary to ensure that the fiber unidirectional tape fits tightly with the mold surface to avoid defects such as wrinkles and bubbles. At the same time, according to the design requirements, some auxiliary materials such as isolation film and breathable felt may be added between different layers to ensure the smooth progress of the laying process and product quality.

[0045] After laying the fiber unidirectional tape, it is vacuumed. The main purpose is to remove the air that may exist between the fiber unidirectional tape layers and between the fiber unidirectional tape and the mold surface. The presence of air will form bubbles during the subsequent heating and pressurizing process, resulting in quality problems such as voids and delamination inside the product, seriously affecting the mechanical properties and appearance quality of the product. By vacuuming, the fiber unidirectional tape layers and the mold surface can form a close fit, improve the density of the product, and create good conditions for the subsequent heating and pressurizing molding.

[0046] Finally, after the vacuumized fiber unidirectional tape laminate structure is placed in the autoclave, the autoclave will gradually increase the temperature and apply pressure according to the set program. After the autoclave is heated and pressurized, the fiber unidirectional tape laminate structure can achieve final molding. At this point, the resin matrix has been fully impregnated with the fiber, and the different layers have also formed an integral structure with high strength and rigidity through the bonding effect of the resin.

[0047] After the first intake duct body 1, the second intake duct body 2, the intake duct body partition 3, and the air filter cover 4 are glued together, the first intake duct body 1 and the second intake duct body 2 are the intake duct skin, forming the intake duct, the intake duct body partition 3 divides the intake duct into two air ducts, the second intake duct body 2 is a hyperbolic surface with a flanged bonding area, the intake duct body partition 3 is located between the first intake duct body 1 and the second intake duct body 2, and forms a flanged flat plate area with the first intake duct body 1 and the second intake duct body 2, forming a frame connected to the intercooler.

[0048] In summary, by increasing the structural rigidity and reducing the structural weight, the reliability in practical applications is enhanced, and it can better cope with various working conditions and maintain stable operation. At the same time, the operating efficiency is also significantly improved, such as reducing energy consumption and increasing working speed, thereby optimizing the overall performance. A series of measures to improve surface quality and reduce the number of fasteners and parts have effectively reduced the maintenance cost of the product during use. The probability of failure caused by looseness, damage, etc. is reduced, which greatly reduces the failure rate of the product and extends the service life. In other words, the structural rigidity is increased, the structural weight is reduced, the structural integrity is good, the surface quality is improved, the number of fasteners and parts is small, the process method is mature and reliable, and the cost is low.

Claims

1. A composite material engine intake duct structure, characterized in that: It comprises an air intake duct first body (1), an air intake duct second body (2), an air intake duct body partition (3) and an air filter cover (4); The first air intake duct body (1) is arranged on one side of the second air intake duct body (2); one end of the air intake duct body partition (3) is fixedly connected to the first air intake duct body (1) and the other end is fixedly connected to the second air intake duct body (2); the air filter cover (4) is arranged on a side of the air intake duct body partition (3) away from the first air intake duct body (1) and is used for connecting to an air filter device.

2. The composite engine intake duct structure according to claim 1, characterized in that: The first air intake duct body (1), the second air intake duct body (2), and the air intake duct body baffle (3) constitute an air intake duct channel 1 for air intake of an intercooler; the first air intake duct body (1), the second air intake duct body (2), the air intake duct body baffle (3), and the air filter cover (4) constitute an air intake duct channel 2 for air intake of an engine.

3. The composite material engine intake structure according to claim 2, characterized in that: The first main body (1) of the air inlet has a C-shaped appearance and an L-shaped cross section.

4. The composite material engine intake duct structure according to claim 3, characterized in that: The front end of the first air inlet body (1) is provided with a sunken area, and the rear end is provided with a flanged flat plate area.

5. The composite engine intake structure according to claim 2, characterized in that: The front end of the second air inlet body (2) is provided with a sunken area, and the rear end is provided with a flanged flat plate area.

6. The composite engine intake structure according to claim 2, characterized in that: A flanged flat plate area is provided at the rear end of the air inlet main body partition (3).

7. The composite material engine intake structure according to claim 2, characterized in that: The first main body (1), the air intake duct second main body (2), the air intake duct main body partition (3), and the air filter cover (4) are carbon fiber composite material laminated parts.

8. The composite engine intake structure according to claim 2, characterized in that: The second main body (2) of the air inlet duct is a double-curved laminate.

9. A method for preparing a composite material engine intake structure, characterized in that: The composite material engine intake duct structure according to any one of claims 1 to 8 comprises the following steps: The first air intake duct body (1), the second air intake duct body (2), the air intake duct body partition (3), and the air filter cover body (4) are formed by heating and pressurizing in an autoclave; The air intake duct first body (1) and the air intake duct second body (2) are connected to form the air intake duct; The air intake duct is connected to the air intake duct main body partition (3) to divide the air intake duct into two air intake ducts.

10. The method for preparing a composite material engine intake structure according to claim 9, characterized in that: The two air passages are an air intake passage 1 and an air intake passage 2.

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