A method of forming a carbon fibre composite material inlet duct

Abstract

The application discloses a forming method of a carbon fiber composite air inlet, belonging to the technical field of aircraft air inlet technology, and comprises the following steps: 1) preparing prepreg; 2) cleaning a mould; 3) blanking; 4) laying an inner skin; according to a layering sequence, the cut prepreg is laid on the effective area of the mould; when laying the first layer of prepreg on the lip R angle, the prepreg is laid and compacted once, and after laying four layers of prepreg, the prepreg is laid and compacted once under vacuum; each compacting lasts more than 15 min; during the vacuum process, a separation film is used to wrap raw silica gel and place the raw silica gel at the lip R angle; the diameter of the raw silica gel is 2+ / -0.2 cm; after the prepreg is laid to half, cold pressing is carried out for pre-compaction; at this time, the raw silica gel fills the lip R angle; 5) curing; 6) demoulding; 7) preparing a honeycomb; 8) positioning the honeycomb; 9) laying an outer skin; and 10) curing; the application designs the lip of the air inlet and the front section of the air inlet to be integrally formed by composite materials, avoids the risk that fasteners enter the engine, and reduces the number of parts.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aircraft, in particular to a forming method of an aircraft air inlet lip section. BACKGROUND

[0002] Carbon fiber reinforced resin matrix composite material has the advantages of high strength, high modulus, light weight, strong designability, etc. In recent years, carbon fiber composite material structural parts have been widely used in the fields of aerospace, weapon equipment, aircraft and ship.

[0003] In recent years, with the increasing demand for stealth design of aircraft, the main components of the unmanned aerial vehicle are reasonably arranged by using electromagnetic wave scattering theory, and the electromagnetic wave is reflected in the non-main threat direction by adopting targeted structure optimization design, so as to reduce the radar reflection cross section of the aircraft structure components as much as possible and reduce the probability of being detected by the enemy radar. The air inlet is the air flow channel of the aircraft engine, and is one of the five components of the aircraft engine and the main component of the aircraft propulsion system. Therefore, the design and manufacture of the air inlet, especially the air inlet lip, are particularly important.

[0004] Some aircraft air inlets are above the back of the aircraft. When the air passes through the air inlet lip, the airflow is divided into two parts, one part enters the front end of the air inlet, and the other part flows along the skin outside the lip. In order to ensure the air inlet efficiency, the shape of the lip is usually complex, and the connection with the skin above or around the lip also needs to be considered. The conventional design is that the lip and the air inlet are separated, the lip is made of metal, and the air inlet is made of composite material. The metal lip and the air inlet are connected by a glue riveting combination process. There are problems such as difficulty in connecting fasteners in local areas and risk of fasteners entering the engine. SUMMARY

[0005] In view of the deficiencies in the prior art, the present application provides a forming method of a carbon fiber composite material air inlet, which integrates the air inlet lip and the front section of the air inlet according to the composite material, and connects the lip and the skin outside the air inlet, thereby avoiding the risk of fasteners entering the engine, reducing the number of parts, reducing the mass of the parts, and improving the surface forming quality of the lip by using a negative mold forming method.

[0006] The purpose of the present application is achieved by a forming method of a carbon fiber composite material air inlet, comprising the following steps:

[0007] Step 1) Prepare carbon fiber / epoxy resin prepreg, cool at room temperature and wait for use;

[0008] Step 2) Clean the mold surface and wait for use, and select a negative mold;

[0009] Step 3) Cutting according to the designed lay-up drawing using an automatic cutting machine;

[0010] Step 4) Inner skin laying according to the lay-up sequence; cutting the prepreg according to the lay-up sequence, lay-up ratio and lay-up direction, laying and compacting the prepreg in the effective area of the mold, when laying and compacting the prepreg in the lip R corner, except for the first layer of prepreg, vacuumizing and compacting once every four layers of prepreg, and each time for more than 15 minutes, during the vacuumizing process, using a release film to wrap the raw silicone and place it at the lip R corner, the raw silicone has a diameter of 2±0.2 cm, and the piece is laid to half, then cold pressing and pre-compacting, and at this time the raw silicone fills the lip R corner;

[0011] Step 5) Putting the product into a hot press for curing, and then removing the bag after cooling and curing;

[0012] Step 6) Installing a drilling jig on the mold to perform edge rolling and hole drilling, and then removing the mold;

[0013] Step 7) Extracting the honeycomb bottom surface according to the numerical model, cutting and chamfering the same size honeycomb using a cutting machine;

[0014] Step 8) Honeycomb positioning;

[0015] Step 9) Outer skin laying according to the lay-up sequence;

[0016] Step 10) Putting the product into a hot press for curing, and then removing the mold and performing subsequent cutting, drilling and inspection to obtain a carbon fiber composite material inlet lip section.

[0017] Further, in step 4), a sacrificial layer is first laid at the edge rolling position, and then pre-vacuumizing for a set time.

[0018] Further, after the first layer of prepreg is laid and the pre-vacuumizing time is set, a pre-prepared carbon twisted wire is placed at the edge rolling R corner for a right angle transition.

[0019] Further, the curing parameters in steps 5) and 10) are:

[0020] Vacuumizing at room temperature, vacuum degree not less than 0.092 MPa, and then curing in the tank after cold pressing test;

[0021] Rising temperature to 125±5℃ at room temperature, rising rate 1.0-2.0℃ / min, medium temperature set to 130℃, when the fastest rising thermocouple rises to 40℃, start pressurizing, until 0.6 MPa starts to hold pressure;

[0022] When the slowest thermocouple rises to 120℃, hold for 120-130 min;

[0023] After cooling at a rate of no more than 2℃ / min to below 80℃, the pressure is removed, and when the temperature of the fastest cooling thermocouple is reduced to below 60℃, the tank is opened, and the curing of the part is completed.

[0024] Further, the honeycomb processing in step 7 specifically comprises: according to the honeycomb core direction in the digital model, the honeycomb size, cutting out a demolding cloth of the same size using a blanking machine, cutting out the honeycomb according to the demolding cloth, then pasting the demolding cloth on a hard backing plate, and cutting out a corresponding shape backing plate; pasting double-sided tape around the backing plate and pasting the honeycomb thereon; according to the chamfer angle required by the honeycomb in the digital model, polishing the edge of the honeycomb using a polisher, and measuring the angle of the honeycomb with a protractor while polishing to ensure that the angle deviation is controlled within ±3°; after the chamfering of the honeycomb is completed, cleaning the debris, particles and other excess materials in the cells with compressed air, and cleaning the surface of the honeycomb with anhydrous ethanol with a clean cloth, then wrapping the honeycomb core with a peelable cloth and a breathable felt in turn, and placing it in an oven for 1h at 70±5℃, then sealing the honeycomb in a sealed bag and transferring it to a clean room.

[0025] Further, the honeycomb positioning in step 8 specifically comprises: pasting the skin honeycomb adhesive film at the position where the inner skin and the honeycomb are pasted, pasting the skin prepreg adhesive film in other areas, and overlapping the adhesive film by 2-4mm, then vacuumizing and compacting, and then placing the honeycomb on the adhesive film and vacuumizing and compacting; using foaming glue to bond at the joint of the honeycomb, trimming and aligning the joint, using adhesive film to fill the gap that cannot be compacted and then pre-vacuumizing, until there is no gap between the honeycomb and the inner skin, and using foaming glue to fill the torn honeycomb and the edge angle and then pre-vacuumizing.

[0026] Further, the outer skin pasting in step 9 specifically comprises: pre-vacuumizing once after the first layer is pasted, then pasting the next layer, and finally pasting a layer of waterproof film on the honeycomb area, overlapping by 2-4mm, and pre-vacuumizing for more than 2h, and using overlapping method between the outer skin pieces, and the overlapping length is 20-30mm, and the joint positions need to be staggered layer by layer.

[0027] Compared with the prior art, the beneficial effects of the present application are:

[0028] 1) The carbon fiber composite material honeycomb sandwich structure is adopted, which effectively reduces the weight of the product while meeting the mechanical properties of the part;

[0029] 2) The hot press tank process is adopted, which reduces the porosity of the composite material and improves the structural strength;

[0030] 3) The cold pressing pre-curing method is adopted, and the product is pre-compacted by a certain thickness of each layer, which avoids the situation that the pre-preg is once pasted too thick, causing the part to be not compacted, wrinkled, bridged, and the internal resin not to be cured, and ensures the internal quality of the part;

[0031] 4) In the process of laying, the raw silica gel is used to assist the R corner area of the lip to compact, which reduces the difficulty of laying in the R corner area, improves the compaction effect between layers, avoids fiber wrinkling, bridging and other situations, and ensures the internal quality of the product. Fill in the R corner area during final curing to reduce the risk of bag explosion;

[0032] 5) Use carbon twisted wire to fill the turned-up right angle area, so that the material sheet can pass smoothly when laying in the right angle area, improve the operability of laying, and reduce the risk of bridging and delamination in the R corner area;

[0033] 6) In order to avoid the situation that the fiber is broken due to grinding when the inlet lip section and the next section of the inlet duct are assembled, and then affect the strength, a sacrificial layer area is added to the grinding area in the laying design, and the corresponding position of the mold is milled to compensate, so as to ensure that there is no step difference in the internal profile of the inlet lip section of the inlet duct after grinding and the next section after assembly. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present application, and those skilled in the art can obtain other drawings according to the provided drawings without creative labor.

[0035] Figure 1 The inlet duct structure prepared by the present application is shown in the schematic diagram.

[0036] Figure 2 The cross-sectional view of the inlet duct prepared by the present application is shown in the schematic diagram.

[0037] Figure 3 The flowchart of the present application is shown in the schematic diagram.

[0038] Figure 4 The mold structure in the present application is shown in the schematic diagram.

[0039] Figure 5 The twisted wire placement in the present application is shown in the schematic diagram.

[0040] Figure 6 The inlet duct prepared by the present application is shown in the actual photo.

[0041] Among them, 100 is the skin, 101 is the lip, 102 is the turned-up edge, 200 is the honeycomb, 300 is the outer skin, 400 is the inlet duct laying mold, 500 is the front baffle, 600 is the rear baffle, 700 is the lip laying mold, and 800 is the ear. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0043] As shown in Figures 1-2 The air inlet duct is a secondary forming structure, including a lip 101 at the front end of the air inlet duct and a flange 102 at the rear end of the air inlet duct, the lip 101 region is only laid with the inner skin 100, and the flange from the middle to the tail is laid with the inner skin 100, the honeycomb 200 and the outer skin 300.

[0044] As shown in Figure 3 A forming method of a carbon fiber composite material air inlet duct, comprising the following steps:

[0045] 1. Material taking;

[0046] The carbon fiber / epoxy resin prepreg is taken out from the cold storage and cooled at room temperature before use.

[0047] 2. Mold processing;

[0048] Anhydrous ethanol is poured onto clean wiping paper or cloth, and the mold surface dust, particulate matter and other excesses affecting the surface quality of the part are wiped off, so that the mold surface is smooth and clean. It is confirmed that the tool surface is not damaged, and the tool cutting line, excess line, coordinate system and other lines are clearly visible. Three times of release agent are applied on the working surface, with an interval of 15 minutes each time, and dried at room temperature for at least 30 minutes after construction. As shown in Figure 4 The mold includes an air inlet duct laying mold 400, the front end of the air inlet duct laying mold 400 is connected with a front baffle 500, the rear end of the air inlet duct laying mold 400 is connected with a rear baffle 600, the outer periphery of the air inlet duct laying mold 400 is sleeved with a lip laying mold, an arc-shaped lip laying surface is formed between the lip laying mold 700 and the air inlet duct laying mold 400, and the front baffle 500 and the rear baffle 600 are provided with lifting lugs 800.

[0049] 3. Prepreg cutting;

[0050] The Catia and Fibersim software are used to make an air inlet duct contour drawing, according to the principle that the seams of layers in the same direction should be staggered by at least 25 mm, the CAD drawing software is used to divide, encode and sort each layer of the prepreg, and a cutting drawing is made. The cutting drawing is imported into an automatic cutting machine to cut the prepreg accurately, and the angle of the prepreg can be ensured to be within 0-5°. After cutting, the prepreg is sorted according to the order of the layers, and it is checked whether the sorted prepreg is complete and undamaged.

[0051] 4. Preparation of the twisted yarn;

[0052] The prepreg and the film are cut into narrow strips with a width of 24 mm, and then the two are laminated together, rolled into a thin round bar, and then placed in a special R5 twisted yarn tool, and the prepreg twisted yarn is compacted under a pressure of 10 MPa at room temperature for 30 min, as shown in Figure 5 .

[0053] 5. Lamination of the prepreg

[0054] First, the lamination of the sacrificial layer is performed at the turning position, and then pre-extraction is performed for 15 min. Then, according to the lamination sequence, the lamination ratio, the lamination direction, etc., the cut prepreg is laminated in the effective area of the mold. After the first layer of fabric is laminated, pre-extraction is performed for 15 min, and the R5 carbon twisted yarn prepared in advance is placed at the R angle of the lip to make a right-angle transition. During this process, the following points should be noted: the fabric overlap width is 20 mm; in order to reduce the gap between each layer of prepreg as much as possible, in addition to laminating and compacting the first layer of prepreg once, after laminating and compacting four layers of prepreg, vacuum extraction and compaction are performed once, and each compaction is performed for more than 15 min. During the vacuum extraction process, the raw silicone rubber is wrapped with a separation film and placed at the R angle of the lip, and the raw silicone rubber is controlled to a diameter of about 2 cm, which facilitates compaction at the R angle. After the material sheet is laminated to half, cold pressing is performed for pre-compaction, and at this time the raw silicone rubber fills the R angle of the lip, reducing the probability of bag rupture.

[0055] 6. Packaging

[0056] After the lamination of the prepreg is completed, the curing auxiliary material is packaged.

[0057] 7. Curing

[0058] The mold is transported to the effective area of the hot press tank, and after leak detection is qualified, curing is performed according to the following curing parameters:

[0059] ① Vacuum extraction at room temperature, the vacuum degree is not less than 0.092 MPa, and after cold pressing test, the tank is filled for curing;

[0060] ② The temperature is increased to 125±5℃ at room temperature, the heating rate is 1.0-2.0℃ / min, the medium temperature is set to 130℃, when the fastest heating thermocouple rises to 40℃, the pressure is increased, and the pressure is maintained when the pressure reaches 0.6 MPa;

[0061] ③ When the slowest thermocouple is heated to 120℃, the temperature is maintained for 120-130 min;

[0062] ④ The temperature is decreased to below 80℃ at a rate of not more than 2℃ / min, and then the pressure is removed, and when the temperature of the fastest cooling thermocouple is reduced to below 60℃, the tank can be opened, and the curing of the part is completed.

[0063] 8. Bag removal

[0064] When the mold temperature needs to be cooled to room temperature, the bag opening process can be performed. Open the vacuum bag and remove the auxiliary materials on the surface of the part, including air-permeable felt, isolation film, and peelable cloth. When cleaning the peelable cloth, handle it carefully to avoid tearing the surface fibers.

[0065] 9. Hole drilling

[0066] Place the bag-opened part together with the mold on the drilling jig, check whether the position of the drilling jig and the part after installation is accurate, and then perform position punching on both sides of the flange.

[0067] 10. Inner skin treatment

[0068] Use 180-240 mesh sandpaper to polish the outer surface of the entire intake duct inner skin to increase its roughness and improve adhesion.

[0069] 11. Honeycomb treatment

[0070] According to the direction of the honeycomb core in the numerical model and the size of the honeycomb, use the cutting machine to cut out a release cloth of the same size, and cut out the honeycomb according to the release cloth. Then, paste the release cloth on a hard backing plate and cut out a corresponding shape backing plate. Paste double-sided tape around the backing plate and paste the honeycomb on it. According to the required chamfer angle of the honeycomb in the numerical model, use a sander to polish the edges of the honeycomb. Measure the angle of the honeycomb with a protractor while polishing to ensure that the angle deviation is within ±3°, meeting the design requirement (±5°). After chamfering the honeycomb, use compressed air to clean the debris and particles in the cells, and use a clean cloth dipped in anhydrous ethanol to clean the surface of the honeycomb. Wrap the honeycomb core with peelable cloth and air-permeable felt in turn, and place it in an oven at 70±5°C for 1 hour. Then, seal the honeycomb in a sealed bag and transfer it to a clean room.

[0071] 12. Honeycomb positioning and pasting

[0072] Lay a layer of skin and core adhesive film between the inner skin and the honeycomb, and lay skin and prepreg adhesive film in other areas. The adhesive film overlaps by 2-4 mm. Then, vacuum and compact for 15 minutes. Next, place the honeycomb on the adhesive film and vacuum and compact for another 15 minutes.

[0073] Use foaming glue to bond the joint of the honeycomb. The joint needs to be trimmed and aligned. For gaps that cannot be compacted, use adhesive film to fill them and then pre-vacuum for 15 minutes until there are no gaps between the honeycomb and the inner skin. For torn honeycombs and edge angle defects (within the allowable range of inspection requirements), use foaming glue to fill them and then pre-vacuum for 15 minutes.

[0074] 13. Outer skin pasting

[0075] According to the design requirements, the outer skin is laid. After the first layer is laid, a pre-extraction of 15 minutes is carried out, and then the next layer is laid. Finally, a layer of Tedlar waterproof film is laid in the honeycomb area, with an overlap of 2-4 mm. The pre-extraction time is more than 2 hours. The outer skin pieces are overlapped, with an overlap length of 25 mm. The joint position needs to be staggered layer by layer. During the vacuum extraction process of the laying layer, the R corner of the lip is a non-laying area, so an isolation film can be used to wrap a raw silicone plug to fill the entire R corner area of the lip, which facilitates the arrangement of the vacuum bag and reduces the probability of bag explosion.

[0076] 14. Curing

[0077] The mold is transported to the effective temperature area of the hot press tank. After the leak test is passed, the part curing is completed according to the following parameters:

[0078] ① Vacuum extraction at room temperature, vacuum degree not less than 0.092 MPa, after passing the cold pressure test, put into the tank for curing;

[0079] ② Warm up to 125±5℃ at room temperature, the heating rate is 1.0-2.0℃ / min, the medium temperature is set to 130℃, when the fastest heating thermocouple rises to 40℃, start to pressurize, until 0.2 MPa starts to keep pressure;

[0080] ③ When the slowest thermocouple is heated to 120℃, keep warm for 120-130 minutes;

[0081] ④ Reduce the temperature to below 80℃ at a rate not greater than 2℃ / min, then remove the pressure, when the fastest cooling thermocouple temperature reduces to below 60℃, the tank can be opened.

[0082] 15. Finally, the cured and cooled parts are demolded and then cut, punched, and inspected. The final product diagram is shown in the following figure. It is particularly noted that when drilling holes in composite parts, the back surface needs to be pressed against a wooden block (or bakelite block) or other methods are taken to prevent delamination at the hole exit.

[0083] The principles of the present application will be further described below:

[0084] The present application mainly realizes the successful implementation of high-difficulty structure by the related process operation in the lip area lay-up manufacturing process. Because the R angle of the first section of the air inlet is small and the shape is converging from outside to inside, it is difficult to lay and compact, and it is easy to have defects such as surface glue deficiency, material deficiency, and delamination. In the manufacturing process, the cold pressing and the method of filling raw silica gel at the bottom R angle to assist compaction can greatly improve the compaction effect of the lay-up and avoid defects. However, due to the relatively small pressure (about 0.1 MPa) of the vacuum pump, the filled raw silica gel cannot be too much to avoid the dispersion of pressure in the pre-evacuation process and affect the compaction. Finally, due to the large applied pressure (0.6 MPa), the entire lip area can be filled and leveled, and the filled raw silica gel can also avoid the situation of bag explosion due to the difficulty of arranging the vacuum bag. The specific principle is as follows:

[0085] Firstly, in the composite lay-up process, pre-evacuation is performed after a certain number of layers are laid, which can greatly compact the fiber layer. However, some R angles and bending areas are difficult to be pre-evacuated due to the small space and the difficulty of arranging the vacuum bag, and there is a great possibility of being in the bridging state. Moreover, if one layer is bridged, the subsequent lay-up in this area will always be bridged, which will eventually lead to product delamination. At this time, suitable pre-evacuation auxiliary tools will be particularly important. Raw silica gel is a kind of elastomer with strong plasticity and certain compressive strength. The use of this material can fully fill and compact the R area. However, unlike the cured silica gel after heating, due to the relatively small pressure of the vacuum pump, too much raw silica gel will disperse and buffer the pre-evacuation pressure due to the elasticity of the raw silica gel itself. Therefore, during the pre-evacuation process, the raw silica gel only needs to be filled to 1-2 cm, which can not only fill the R angle and facilitate the arrangement of the vacuum bag, but also not affect the vacuum compaction too much, thereby improving the pre-evacuation effect and product quality.

[0086] Secondly, for complex structures, for small R angles and many bending areas, as the number of layers increases, the effect of the simple vacuum pump (≤0.1 MPa) pressure will be greatly weakened, and there may still be problems of bridging and wrinkling between layers in these areas. The cold pressing pre-solidification method is to place the workpiece in a hot pressing tank and apply ≥0.1 MPa pressure at low or room temperature to assist the compaction of the material sheet that cannot be compacted by the vacuum pump. Moreover, due to the large pressure applied by the hot pressing tank, the R angle and bending area can be filled with raw silica gel to reduce the risk of bag explosion.

[0087] In addition, the application of carbon twisting yarn is to reduce the actual operation difficulty from the perspective of layer structure design. The use of carbon twisting yarn can avoid the formation of bridging due to the difficulty in filling in the R corner during subsequent layering process. After the first layer of plain fabric with good ductility and easy to lay is laid, the carbon twisting yarn obtained by pressing the special twisting yarn tool according to different R angle sizes is used to fill the right angle R area, so that the material sheet can pass through the area smoothly when it is laid, and the operability of the layer is improved, and the risk of bridging and delamination in the R corner area is reduced.

[0088] When the air inlet lip section is matched with the next section of the air inlet, the glue joint assembly area will be repaired and polished, which will cause fiber breakage and affect the strength, and also affect the internal aerodynamic profile. In the early stage of layer design and mold design, a sacrificial layer design and mold milling surface processing compensation are specially added to the polishing area in the later stage, which can ensure that there is no step difference in the internal profile of the air inlet lip section of the air inlet after polishing and after the next section of the assembly.

[0089] The four improved schemes are adopted to realize the production and manufacturing of the air inlet of the present application, realize the replacement of the metal lip, avoid the risk of fasteners entering the engine, reduce the number of parts, and reduce the weight of the parts. At the same time, the air inlet lip is formed by a negative mold, which improves the surface forming quality of the lip. The finally formed air inlet is shown in Figure 6 .

[0090] The above examples are only used to help understand the method of the present application and its core idea. It should be noted that for those skilled in the art, without departing from the principles of the present application, the present application can be improved and modified, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A method of forming a carbon fiber composite material inlet duct, characterized by, Comprise the following steps: Step 1) prepare carbon fiber / epoxy resin prepreg, cool at room temperature for standby; Step 2) clean the mold surface for standby, select negative mold; Step 3) use automatic cutting machine according to the designed lay-up diagram to cut; Step 4) according to the lay-up sequence, lay-up ratio and lay-up direction, the cut prepreg is laid on the effective area of the mold, when laying the R angle of the lip, except that the first layer of prepreg is laid and compacted once, every four layers of prepreg is laid and compacted once after vacuumizing, and the vacuumizing process is carried out for more than 15 minutes each time, during the vacuumizing process, the fresh silicone is wrapped with isolation film and placed at the R angle of the lip, the diameter of the fresh silicone is 2±0.2 cm, the material piece is laid to half, and then cold pressing is carried out for pre-compaction, and the fresh silicone fills the R angle of the lip at this time; Step 5) send the workpiece into the hot press tank for curing, and then carry out debagging after curing and cooling; Step 6) install the drilling jig tool on the mold to carry out edge turning and hole drilling of the workpiece, and then demold; Step 7) according to the numerical model, the honeycomb bottom surface is extracted, the same size honeycomb is cut by using the cutting machine, and then cutting and chamfering are carried out, and the honeycomb processing specifically comprises: according to the honeycomb core direction in the numerical model and the size of the honeycomb, the same size release film is cut by using the cutting machine, the honeycomb is cut according to the release film, then the release film is pasted on a hard backing plate, and the corresponding shape backing plate is cut out; the periphery of the backing plate is pasted with double-sided adhesive and the honeycomb is pasted thereon; according to the chamfer angle required by the honeycomb in the numerical model, the honeycomb edge is polished by using a polisher, and the honeycomb angle is measured by using an angle ruler during polishing, so as to ensure that the angle deviation is controlled within ±3°; after the chamfering of the honeycomb is completed, the compressed air is used to clean the debris, particles and other excess substances in the hole grid, and the honeycomb surface is cleaned with anhydrous ethanol by using a clean cloth, and the honeycomb core is wrapped with a peelable cloth and a breathable felt in turn, and is placed in an oven for heat preservation at 70±5℃ for 1h, and then the honeycomb is sealed in a sealed bag and transported to a clean room; Step 8) honeycomb positioning, specifically comprising: laying the skin honeycomb adhesive film at the position where the inner skin and the honeycomb are pasted, laying the skin prepreg adhesive film in other areas, the adhesive film is overlapped by 2-4mm, then vacuumizing and compacting, then placing the honeycomb on the adhesive film, vacuumizing and compacting; the joint of the honeycomb is bonded with foaming glue, the joint is trimmed and aligned, and for the gap that cannot be compacted, the gap is filled with adhesive film and then pre-vacuumized until there is no gap between the honeycomb and the inner skin, and for the torn honeycomb and the edge angle, the foaming glue is used to fill and then pre-vacuumized; Step 9) according to the lay-up sequence, the outer skin is laid; Step 10) send the workpiece into the hot press tank for curing, and then carry out demolding and subsequent cutting, drilling and inspection work to obtain the carbon fiber composite air inlet lip section.

2. A method of forming a carbon fibre composite inlet sp i re according to claim 1, wherein, In step 4), the sacrificial layer is laid at the edge turning position first, and then pre-vacuumized for a set time.

3. A method of forming a carbon fibre composite inlet sp i re according to claim 2, wherein, After the first layer of prepreg is laid and pre-vacuumized for a set time, the carbon twisted wire prepared in advance is placed at the edge turning R angle for right angle transition.

4. A method of forming a carbon fibre composite inlet spool according to any one of claims 1 to 3, wherein, The curing parameters in steps 5) and 10) are: Vacuumizing at room temperature, the vacuum degree is not less than 0.092 MPa, and the tank is filled after cold pressing test; Ramp to 125 ± 5 °C at 1.0-2.0 °C / min, medium temperature set at 130 °C, when the fastest thermocouple rises to 40 °C, start to pressurize, until 0.6 MPa, start to hold pressure; When the slowest thermocouple rises to 120 °C, hold for 120-130 min; Cool down to below 80 °C at a rate of no more than 2 °C / min, then remove the pressure, when the fastest thermocouple temperature decreases to below 60 °C, open the tank, complete the curing of the parts.

5. A method of forming a carbon fibre composite inlet spool as claimed in any one of claims 1 to 3, wherein, Step 9) The outer skin laying specifically includes: after the first layer is laid, pre-extract once, then lay the next layer, finally lay a layer of waterproof film in the honeycomb area, overlap 2-4 mm, pre-extract for 2 h or more, the outer skin pieces are overlapped, the overlap length is 20-30 mm, and the joint positions need to be staggered layer by layer.

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