Manufacturing method of honeycomb sandwich composite material wedge-shaped trailing edge part

Abstract

The invention belongs to the technical field of aviation composite material component manufacturing, and relates to a honeycomb sandwich composite material wedge-shaped trailing edge part manufacturing method. Comprising the following steps: 1) manufacturing a skin and a rear beam; 2) preforming the honeycomb core; 3) gluing the honeycomb core and the skin; (4) the rear beam and the rear beam male die are fixed to a rear beam forming platform; (5) a limiting block is installed on the rear beam forming platform; (6) an adhesive film is pasted on the surface of the rear beam, and polystyrene foam is coated; (7) the skin honeycomb core assembly and the rear beam are glued and positioned to form a wedge-shaped trailing edge; 8) packaging the vacuum bag and installing a fixed clamping plate; (9) removing the vacuum bag for detection after vacuumizing and pre-compacting, and reassembling the skin honeycomb core assembly if the detection is not qualified; and (10) the step (8) is repeated for vacuum compaction and curing.

Description

Technical Field

[0001] The invention belongs to the technical field of aviation composite material component manufacturing, and relates to a method for manufacturing a wedge-shaped trailing edge part of a honeycomb sandwich composite material. Background Art

[0002] Composite materials are increasingly used in the aviation field due to their strong designability, light weight, high specific strength / specific modulus, and superior corrosion resistance, especially in aircraft rudders, elevators, flaps, ailerons, trimming plates and other control surface parts. At present, almost all domestic and foreign aircraft parts of this type are made of composite materials, and the design structure is basically the same, mainly including leading edge skin, front beam, upper / lower wall panels, wedge-shaped trailing edge and other parts. Among them, the wedge-shaped trailing edge generally adopts a honeycomb sandwich structure in order to effectively reduce weight, which is mainly composed of skin, honeycomb core, rear beam and other parts (see attached Figure 1 ), the manufacturing method includes one-time co-curing molding and secondary bonding curing molding. In order to reduce the manufacturing risk, the current production units mainly use the secondary bonding method, that is, the skin and the back beam are first formed separately by the male mold and the edges are accurately trimmed, and then the honeycomb core is directly glued and installed with the skin, squared on the flat mold (fixed blocks are installed on the flat mold at the same time), and finally the filling block is placed at the open end of the back beam and then placed on the flat mold, and then the vacuum bag is encapsulated and put into the tank for curing (see attached Figure 2 ), this method has one side attached to the mold, and the two sides are subjected to uneven force, which affects the part to one side after molding, affecting the shape and size of the part, and the difference in the bonding quality on both sides after non-destructive testing is large, affecting the non-destructive testing pass rate, the other side is subjected to greater force, the top of the honeycomb core shrinks severely, resulting in holes in the matching part with the top of the skin, causing the part to be scrapped, and in addition, since the film mold is attached to one side, the honeycomb core cannot transmit the pressure, resulting in serious pinholes on the surface after painting, affecting the surface quality, and increasing the weight of the part and the bonding strength of the paint layer after putty treatment, etc. The above problems have resulted in the current pass rate of such parts being less than 50%. Summary of the invention

[0003] The purpose of the present invention is to improve the manufacturing quality and first pass rate of honeycomb sandwich composite wedge-shaped trailing edge parts, and solve the problems of uneven force on both sides of the current "lying flat" manufacturing scheme affecting the external dimensions, the quality of the bonding between the skin and the honeycomb core, the easy shrinkage of the honeycomb core, and pinholes on the painted surface. After analysis and research and trial production of test pieces, a "standing" secondary bonding installation and positioning method was determined (see attached). Figure 5 , Attachment Figure 6), and by adding auxiliary positioning devices to the rear beam forming male mold, the skin, honeycomb core, and rear beam are precisely positioned for gluing and installation, and fixed during the heating and curing process. First, the honeycomb core is pre-shaped to improve the shrinkage resistance of the honeycomb core, and it is glued and installed with the skin. Then the cut rear beam is placed on the forming male mold according to the outer shape line, and the positioning limit blocks of the lower end face of the skin are installed in sequence. Then the skin glued with the honeycomb core is placed on the rear beam, and finally the vacuum bag is encapsulated and the outer shape fixing card is installed and put into the autoclave for curing. The "standing" secondary gluing method is adopted to ensure that the skin is uniformly accepted on both sides, solve the problems of outer size deviation, easy shrinkage of the honeycomb core, difference in gluing quality on both sides, and pinholes in the mold surface spraying. The honeycomb core is pre-shaped, which effectively improves the shrinkage resistance of the honeycomb core, and achieves 100% qualified wedge-shaped trailing edge parts of honeycomb sandwich composite materials at one time, ensuring the development and batch production progress of model aircraft, saving costs, etc.

[0004] Technical Solution

[0005] The method of the present invention relates to a "standing type" secondary bonding method and device, which mainly includes the steps of manufacturing skin and rear beam, preforming of honeycomb core, bonding of honeycomb core and skin, positioning of rear beam, installation of positioning limit block at the lower end face of skin installation, paving of foam glue and film, bonding and positioning of skin honeycomb core assembly and rear beam, installation of stopper, packaging of vacuum bag, installation of fixed cardboard, vacuum pre-compaction, curing, parts inspection, etc. The specific steps and requirements are as follows:

[0006] 1) Manufacturing of skin and rear beam: Use positive molds to solidify and shape the skin and rear beam respectively according to the drawings of the skin and rear beam and the requirements of relevant process specifications. In order to ensure the subsequent bonding quality between the inner surface of the skin and the honeycomb core, it is strictly forbidden to use mold release agents on the surface of the positive mold for skin molding. A layer of mold release cloth should be laid in advance and vacuum compacted to ensure that there are no wrinkles. After the curing and molding is completed, the excess should be cut according to the part outline for standby use.

[0007] 2) Honeycomb core pre-shaping: Select the adhesive film material for bonding the skin and honeycomb core specified in the drawing, cut the material strip with a width of 100mm by automatic or manual cutting, and stick a piece of adhesive film on the surface of the honeycomb core at an interval of 100mm (see attached Figure 3 ), lay a layer of adhesive film on the corresponding position of the other side of the honeycomb core, and then place it on the flat mold with the release cloth laid on it, and press the attachment Figure 3 Baffles and blocks machined from phenolic or epoxy laminated cloth are placed in position and fixed with sub-sensitive tape. The block should have the same shape as the end face of the honeycomb core, and the height of the baffle should be the same as the height of the honeycomb core. Finally, non-porous isolation and breathable felt are laid in turn, and vacuum bags are used for packaging. The vacuum is evacuated to 0.02-0.03MPa, and the curing parameters of the film are used for heating and curing.

[0008] After test verification, it is found that after the pre-forming with adhesive film, the tail edge honeycomb core has good compression resistance in the force direction, and after test verification, the adhesive film is applied to the entire surface of the honeycomb core on both sides or one side, which leads to increased rigidity in the length direction of the tail edge honeycomb core, and there is a large stress when bonding with the skin, which makes the parts easy to deform. After many improvements, a 100mm wide and spaced adhesive film is used for pre-forming, which improves the compression resistance of the honeycomb core in the force direction and maintains the deformation of the honeycomb core in the length direction, avoids the generation of stress during the bonding process, and ensures the quality and appearance of the bonding between the skin and the honeycomb core. In addition, it is verified that no stop strips or blocks are placed during the pre-forming process, and the honeycomb core is severely compressed and deformed due to the lateral force. In addition, a vacuum pressure of 0.02-0.03MPa is most suitable, and a large vacuum pressure will affect the deformation of the honeycomb core.

[0009] 3) Glue the honeycomb core to the skin: Cut a 3mm wide foam glue, place it on the top of the inner surface of the skin, and compact it with a hard tool, then lay the film on both sides of the honeycomb core, and reserve about 2mm on the top without the film to ensure the foam filling. It is strictly forbidden to wrap the top of the honeycomb core with the film, and place the honeycomb core with the film on the inner surface of the skin. The laying process requires the cooperation of multiple people. First, open the open end of the skin, and then place the honeycomb core. Then check whether the exposed end face of the honeycomb core is flush with the inner surface of the skin. If not, trim the end face of the honeycomb core to adjust it to meet the requirements, and finally form a skin honeycomb core assembly (see attached Figure 4 ).

[0010] After experimental verification, it was found that filling the top of the skin with 3mm wide foam can effectively fill the gap between the top of the honeycomb core and the skin, improve the pass rate of non-destructive testing, and reserve about 2mm on the top of the honeycomb core without adhesive film, which can effectively ensure that the foam fills the honeycomb core pores, and the honeycomb core can shrink slightly during the foaming process without affecting the overall offset of the honeycomb core.

[0011] 4) Positioning of rear beam: The innovative "standing" secondary bonding process method is used to start the assembly and installation of various parts. First, the trimmed rear beam is placed back into the forming male mold according to the outline, and pressed to ensure that it is completely attached. At the same time, the lower edges on both sides are fixed to the mold with high temperature resistant pressure-sensitive tape.

[0012] The "standing" secondary bonding method is completely different from the current "lying" secondary bonding method in terms of assembly positioning and fixing methods of each part, stress conditions during curing, etc. It has been verified by experiments that it effectively ensures uniform acceptance on both sides of the skin, solves the problems of dimensional deviation, honeycomb core shrinkage, difference in bonding quality on both sides, and paint pinholes on the mold surface. In addition, the device design adopted by the present invention fully utilizes the rear beam forming positive mold. Since the opening rebounds after the rear beam is demolded, it affects the assembly effect of the rear beam. In order to meet the requirements, a high-temperature resistant pressure-sensitive tape is used to fix it to the mold.

[0013] 5) Installation of positioning limit block on the lower end face of the skin installation: The design end face is attached Figure 5-2 The thickness of the stopper in contact with the lower end surface of the skin is designed to be 2.5 mm, the width is 100 mm, and the contact surface with the vacuum bag is at an angle of 30° (see attached Figure 5-4 ). Figure 5 The limit blocks are installed at the same position on both sides of the rear beam forming male mold. The interval between the limit blocks is 600mm~800mm. The limit blocks are fixed to the rear beam forming male mold platform with screws (see attached Figure 5-5 ), before installing the limit block, a layer of release cloth should be laid on the contact surface with the rear beam.

[0014] In order to avoid the skin honeycomb core assembly sliding downward under the pressure of the vacuum bag and the autoclave during the heating and pressurizing curing process, which affects the external dimensions of the wedge-shaped trailing edge parts and fails to meet the assembly requirements; on the other hand, it causes the honeycomb core to be compressed and deformed, which affects the non-destructive testing. The limit block is innovatively designed to support the lower end face of the skin to limit the downward movement and ensure its assembly position and dimensional accuracy. After many improvements and test verifications, the thickness of the contact part between the limit block and the lower end face of the skin is very critical. It is designed to be 1mm thicker than the skin as the best, and the contact surface with the vacuum bag should maintain a smooth transition of 30°, effectively avoiding the vacuum bag bridging at the contact part between the limit block and the lower end face of the skin, affecting the compaction of the skin and the rear beam bonding part and the local protrusion of the surface; on the other hand, the limit block of the present invention adopts a discontinuous idea of ​​setting one at an interval of 600mm to 800mm. It has been verified that it fully meets the function of limiting the downward movement of the skin, ensuring that the vacuum bag between the limit blocks is in full contact with the skin and the rear beam, and effectively ensuring the compaction and surface flatness of the bonding part between the skin and the rear beam. Experimental verification has shown that excess glue flows from the adhesive film between the skin and the rear beam during the curing process. If the release cloth is not laid at the contact area between the limit block and the rear beam, it is easy to cause adhesion to the surface of the rear beam, which will damage the surface fibers when removed after curing.

[0015] 6) Laying of foam glue and film: Use sandpaper to gently polish the outer surface of the rear beam, and clean it with a vacuum cleaner and alcohol. Then lay a layer of film on the entire surface of the rear beam. The film is required to be laid flat and no wrinkles are allowed. Finally, lay a layer of foam glue on the interface between the rear beam and the honeycomb core glue according to the requirements of the drawing.

[0016] 7) Positioning of skin honeycomb core assembly and rear beam: According to the requirements of the drawing, place the skin honeycomb core assembly on the rear beam with the adhesive film paved, with the edge of the rear beam end as the reference. When placing, the skin opening needs to be properly opened to ensure that the placement does not affect the slippage of the adhesive film on the surface of the rear beam to form wrinkles, or the adhesive film is partially missing. Then check whether the matching relationship between the lower end face of the skin honeycomb core assembly and the contact part of the limit block is uniform, and whether the two ends are aligned with the edge of the rear beam end. Otherwise, adjust to meet the requirements (see attached Figure 5 ).

[0017] 8) Stopper installation: Figure 3 The two stoppers are wrapped with demoulding cloth respectively, and then filled and placed at the two ends of the skin honeycomb core assembly according to the corresponding relationship of the shapes, so as to support the end skin to cause the end honeycomb core to shrink or collapse during the compression process.

[0018] 9) Packaging vacuum bag: Lay non-porous isolation and breathable felt on the assembled honeycomb sandwich wedge-shaped trailing edge parts (including the limit block) in sequence (the position for placing the pallet should be reduced and a layer of glass cloth should be laid), and use vacuum bag packaging to evacuate to about 0.03MPa.

[0019] 10) Install the fixed card: Figure 6 It indicates that all the card boards 6-1 are placed in sequence. Note that the card board limit slot 6-2 should completely correspond to the position of the breathable felt in "9) packaging vacuum bag" when placing, so as to avoid getting stuck in the breathable felt position and affecting the limit accuracy. Then, use positioning pins and screws to fix all the card board bases 6-3 at once.

[0020] The design and application of the pallet are also the key to the invention. The application of the pallet ensures the precise positioning and fixation of the skin honeycomb core assembly and the rear beam in the height direction during the pressurization process of the "standing" method, avoiding the skin honeycomb core assembly from leaning to one side during the vacuum pressure or tank pressure, or distortion and deformation in the length direction, easy shrinkage of the honeycomb core, and other problems. At the same time, the pressure on both sides of the wedge-shaped trailing edge parts of the sandwich composite material is the same and uniform during the curing process, ensuring the consistency of the quality of the two sides of the part surface and the shape that fully meets the requirements of the drawing. In order to satisfy the fixed limit function, minimize the number of pallets used, and reduce the impact of the pallets on the vacuum bag, after experimental verification, it was determined that a pallet was designed at each end and a pallet was designed every 1.1m in the middle to complete the design and manufacture of the pallet.

[0021] 11) Vacuum pre-compaction: Continue to vacuum until the pressure reaches above 0.095MPa, cold pump and maintain pressure for 60 minutes, then remove the pallet and vacuum bag, check that the clearance between the lower end face of the skin honeycomb core assembly and the contact part of the limit block should be uniform and less than 2mm, otherwise the skin honeycomb core assembly needs to be removed, repositioned and vacuum fixed.

[0022] 12) Curing: Follow steps 9) and 10 again to seal the vacuum bag and install the fixed pallet, and evacuate until the pressure reaches above 0.095MPa, then put it into the tank for heating and pressurization for curing, heat and pressurize it at a maximum heating rate of 1.5℃ / min, and the tank pressure must reach 0.20MPa~0.23MPa before the temperature reaches 60℃. Continue to heat to 180℃±5℃ under pressure for 120min~180min, and finally cool it down to below 60℃ at a maximum cooling rate of 1.5℃ / min before unloading the pressure and taking it out of the tank.

[0023] The application of tank pressure parameters of 0.20MPa~0.23MPa is also the key to the invention, which is determined through a large number of tests and verifications. The tests verified that when the tank pressure is less than 0.2MPa, the bonding strength between the skin and the honeycomb core is low, and debonding defects are found in non-destructive testing; when the tank pressure exceeds 0.23MPa, the outer surface of the skin sinks and the external dimensions do not meet the drawing requirements.

[0024] 13) Parts inspection: After curing is completed, check whether there are any defects in the outer surface quality, and place the parts on a flat mold or inspection platform to check the straightness, and check whether the relative position and size of the skin and rear beam meet the requirements of the drawing, and then send them to the testing unit for ultrasonic testing, X-ray testing, etc.

[0025] Beneficial effects:

[0026] The present invention provides a method for manufacturing a wedge-shaped trailing edge part of a honeycomb sandwich composite material, which has good processability compared with the prior art. The beneficial effects of the present invention are that a "standing" secondary gluing installation and positioning method and device are used for the first time, which effectively solves the problems of the current "lying" manufacturing method caused by uneven force on both sides of the skin, easy shrinkage of the honeycomb core, difference in gluing quality between the skin and the honeycomb core, and pinholes in the mold surface spray paint, thereby improving the manufacturing quality and efficiency of such parts, increasing the first-time qualified rate of manufacturing acceptance, and saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention includes 6 drawings, and the drawings and the descriptions of the drawings are as follows:

[0028] Figure 1 It is a schematic diagram of the wedge-shaped trailing edge structure of a honeycomb sandwich composite material, wherein: 1-1 skin, 1-2 honeycomb core, 1-3 rear beam.

[0029] Figure 2 It is a schematic diagram of the combination of the "lying flat" manufacturing method, wherein: 2-1 is a flat mold, 2-2 is a positioning block, and 2-3 is a rear beam filling block.

[0030] Figure 3 It is a schematic diagram of honeycomb core pre-molding, wherein: 3-1 honeycomb core pre-molding height direction baffle, 3-2 honeycomb core pre-molding end block, 3-3 honeycomb core pre-molding adhesive film.

[0031] Figure 4 This is a schematic diagram of the installation of the skin and the honeycomb core, where: 4-1 The top of the inner wall of the skin is filled with foam.

[0032] Figure 5It is a schematic diagram of the installation of the skin, honeycomb core and rear beam, where: 5-1 is the front beam forming punch, 5-2 is the skin installation lower end surface positioning limit block 1, 5-3 is the skin installation lower end surface positioning limit block 2, 5-4 is the limit block 30° inclined surface, and 5-5 is the rear beam forming positive mold platform.

[0033] Figure 6 This is a schematic diagram of the installation and fixation of the wedge-shaped trailing edge, where: 6-1 is an outer shape fixing card plate, 6-2 is a card plate limiting card slot, and 6-3 is a card plate fixing base. DETAILED DESCRIPTION

[0034] The present invention provides

[0035] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0036] A certain type of honeycomb sandwich rear edge assembly (the appearance and structure are the same as the attached Figure 2 , 3200mm long, 50mm high) is used as an example to explain in detail that the method of the present invention mainly includes the steps of manufacturing skin and back beam, pre-forming of honeycomb core, gluing of honeycomb core and skin, positioning of back beam, installation of positioning limit block at the lower end face of skin installation, paving of foam glue and film, gluing and positioning of skin honeycomb core assembly and back beam, installation of stopper, packaging vacuum bag, installation of fixed card board, vacuum pre-compaction, curing, parts inspection, etc. The specific steps and requirements are as follows:

[0037] 1) Skin and rear beam manufacturing: Lay a layer of demoulding cloth on the surface of the skin forming positive mold and vacuum compact it. Apply two coats of liquid demoulding agent on the rear beam forming positive mold. Then use T300 carbon fiber fabric prepreg and lay 8 layers in sequence according to the layer requirements of the drawing. Vacuum compact it every three layers. Finally, cure it according to the process specifications specified in the drawing. After curing and molding, cut the excess according to the part outline for standby use.

[0038] 2) Honeycomb core pre-forming: Select the high temperature curing structural adhesive film material specified in the drawing, cut the material strip with a width of 100mm by automatic feeding, and stick a piece of adhesive film on the surface of the pre-prepared wedge-shaped NH-1 series honeycomb core at an interval of 100mm (see attached Figure 3 ), lay a layer of high temperature curing structural adhesive film at the interval position on the other side of the honeycomb core, and then place it on the flat mold with the release cloth laid on it, press the attachment Figure 3 Baffles and blocks machined from phenolic laminated cloth are placed in position and fixed with sub-sensitive tape. The block should have the same shape as the end face of the honeycomb core, and the height of the baffle should be the same as the height of the honeycomb core. Finally, non-porous isolation membrane and breathable felt are laid in turn, and vacuum bags are used for packaging. The vacuum is evacuated to 0.02-0.03MPa, and the curing parameters of the film are used for heating and curing. After curing, the baffles are removed.

[0039] 3) Glue the honeycomb core to the skin: Cut a 3mm wide piece of high-temperature curing structural filling foam glue, place it on the top of the inner surface of the skin, and compact it with a hard tool, then lay the film on both sides of the honeycomb core, and reserve about 2mm on the top without the film to ensure the foam filling. It is strictly forbidden to wrap the top of the honeycomb core with the film, and place the honeycomb core with the film on the inner surface of the skin. The laying process requires the cooperation of multiple people. First, open the open end of the skin, and then place the honeycomb core. Then check whether the exposed end face of the honeycomb core is flush with the inner surface of the skin. If not, trim the end face of the honeycomb core to adjust it to meet the requirements, and finally form a skin honeycomb core assembly (see attached). Figure 4 ).

[0040] 4) Positioning of rear beam: The innovative "standing" secondary bonding process method is used to start the assembly and installation of various parts. First, the trimmed rear beam is placed back into the forming male mold according to the outline, and pressed to ensure that it is completely attached. At the same time, the lower edges on both sides are fixed to the mold with high temperature resistant pressure-sensitive tape.

[0041] 5) Limit block installation: The design end face is attached Figure 5-2 The thickness of the stopper in contact with the lower end surface of the skin is designed to be 2.5 mm, the width is 100 mm, and the contact surface with the vacuum bag is at an angle of 30° (see attached Figure 5-4 ). Figure 5 The limit blocks are installed at the same position on both sides of the rear beam forming male mold. The interval between the limit blocks is 600mm~800mm. The limit blocks are fixed to the rear beam forming male mold platform with screws (see attached Figure 5-5 ), before installing the limit block, a layer of release cloth should be laid on the contact surface with the rear beam.

[0042] 6) Laying foam glue and film on the surface of the rear beam: Use 180# sandpaper to gently polish the outer surface of the rear beam, and clean it with a vacuum cleaner and alcohol. Then, lay a layer of high-temperature curing structural adhesive film on the contact surface between the rear beam and the skin and honeycomb core. The adhesive film is required to be laid flat and no wrinkles are allowed. Finally, lay a layer of high-temperature curing structural filling foam glue on the interface between the rear beam and the honeycomb core.

[0043] 7) Positioning of skin honeycomb core assembly and rear beam: According to the requirements of the drawing, place the skin honeycomb core assembly on the rear beam with the adhesive film paved, with the edge of the rear beam end as the reference. When placing, the skin opening needs to be properly opened to ensure that the placement does not affect the slippage of the adhesive film on the surface of the rear beam to form wrinkles, or the adhesive film is partially missing. Then check whether the matching relationship between the lower end face of the skin honeycomb core assembly and the contact part of the limit block is uniform, and whether the two ends are aligned with the edge of the rear beam end. Otherwise, adjust to meet the requirements (see attached Figure 5 ).

[0044] 8) Stopper installation: Figure 3The two stoppers are wrapped with demoulding cloth respectively, and then filled and placed at the two ends of the skin honeycomb core assembly according to the corresponding relationship of the shapes, so as to support the end skin to cause the end honeycomb core to shrink or collapse during the compression process.

[0045] 9) Packaging vacuum bag: Lay non-porous isolation film and breathable felt on the assembled honeycomb sandwich wedge-shaped trailing edge parts (including limit blocks) in sequence (the position for placing the pallet should be reduced and a layer of glass cloth should be laid), and use vacuum bag packaging to evacuate to about 0.03MPa.

[0046] 10) Install the fixed card: Figure 6 It indicates that all the card boards 6-1 are placed in sequence. Note that the card board limit slot 6-2 should completely correspond to the position where the breathable felt is not dropped, so as to avoid the breathable felt being stuck and affecting the limit accuracy. Then, all the card board bases 6-3 are fixed at once using positioning pins and screws.

[0047] 11) Vacuum pre-compaction: Continue to vacuum until the pressure reaches above 0.095MPa, cold pump and maintain pressure for 60 minutes, then remove the pallet and vacuum bag, check that the clearance between the lower end face of the skin honeycomb core assembly and the contact part of the limit block should be uniform and less than 2mm, otherwise the skin honeycomb core assembly needs to be removed, repositioned and vacuum fixed.

[0048] 12) Curing: Follow steps 9) and 10 again to seal the vacuum bag and install the fixed pallet, and evacuate until the pressure reaches above 0.095MPa, then put it into the tank for heating and pressurization for curing, heat and pressurize it at a maximum heating rate of 1.5℃ / min, and the tank pressure must reach 0.20MPa~0.23MPa before the temperature reaches 60℃. Continue to heat to 180℃±5℃ under pressure for 120min~180min, and finally cool it down to below 60℃ at a maximum cooling rate of 1.5℃ / min before unloading the pressure and taking it out of the tank.

[0049] 13) Parts inspection: After curing is completed, check whether there are any defects in the outer surface quality, and place the parts on a flat mold or inspection platform to check the straightness, and check whether the relative position and size of the skin and rear beam meet the requirements of the drawing, and then send them to the testing unit for ultrasonic testing, X-ray testing, etc.

Claims

1. A method for manufacturing a wedge-shaped trailing edge part of a honeycomb sandwich composite material, characterized in that: The following steps are involved: 1) Manufacturing skin and rear beam; 2) Preformed honeycomb core; 3) Gluing of honeycomb core and skin; 4) Fix the rear beam and the rear beam male mold on the rear beam forming platform; 5) Install the limit block on the rear beam forming platform; 6) Paste the adhesive film on the surface of the rear beam and apply the foam glue; 7) Glue the skin honeycomb core assembly and the rear beam to form a wedge-shaped trailing edge; 8) Pack the vacuum bag and install the fixed card; 9) After vacuum pre-compaction, remove the vacuum bag for testing. If the test fails, reassemble the skin honeycomb core assembly; 10) Repeat step 8) to perform vacuum compaction and solidification.

2. The method according to claim 1, characterized in that: 1), the manufacturing process of the skin and rear beam is as follows: Lay a layer of demoulding cloth on the surface of the skin forming positive mold and vacuum compact it. Apply two coats of liquid demoulding agent on the rear beam forming positive mold. Then use T300 carbon fiber fabric prepreg to lay the layers according to the requirements of the pattern layer. Lay 8 layers in sequence. Vacuum compact it every three layers. Finally, cure it according to the process specifications. After curing and molding, cut the excess according to the part outline for standby use.

3. The method according to claim 2, characterized in that: 2), the honeycomb core preforming process is as follows: Cutting the high temperature curing structural adhesive film material into tapes with a width of n; Adhesive tapes are pasted on both sides of the wedge-shaped NH-1 series honeycomb core at intervals of n; the tapes on both sides are pasted alternately; Adhere the stop strip under the honeycomb core with the adhesive tape by using the pressure-sensitive adhesive tape, and adhere the stop blocks at both ends of the honeycomb core by using the pressure-sensitive adhesive tape; Finally, lay the non-porous isolation film and breathable felt, seal it with a vacuum bag, evacuate to 0.02-0.03MPa, heat and cure it according to the curing parameters of the film, and remove the block after curing.

4. The method according to claim 3, characterized in that: 3), the bonding process of the honeycomb core and the skin is as follows: Fill the top of the inner surface of the skin with foam glue and compact it; Lay adhesive film on both sides of the honeycomb core and leave 2mm width area on both sides of the top without laying adhesive film; Place the honeycomb core with the adhesive film on the inner surface of the skin; Check whether the exposed end face of the honeycomb core is flush with the scoring line on the inner surface of the skin. If not, correct the honeycomb core; A skin honeycomb core assembly is formed.

5. The method according to claim 4, characterized in that: 4), the trimmed rear beam is placed back into the rear beam forming positive mold; at the same time, the lower edge of the rear beam is fixed to the mold using a high temperature resistant pressure sensitive tape, and then the rear beam and the rear beam forming positive mold are placed on the rear beam forming positive mold platform.

6. The method according to claim 5, characterized in that: 5), the limit block is a bent structure, one horizontal side is in contact with and fixed to the rear beam forming male mold platform, one oblique side is in contact with the rear beam and the rear beam forming male mold; the other oblique side is the vacuum bag contact surface; the contact surface between the limit block and the rear beam is paved with a demoulding cloth; The top of the limit block is flush with the lower end surface of the skin; the angle between the two beveled sides is 30°, and the thickness of the connection between the two beveled sides is 2.5mm; the width of the limit block is 100mm; the limit blocks are arranged correspondingly on both sides of the rear beam and the rear beam forming positive mold, and the interval between the two limit blocks is 600mm to 800mm.

7. The method according to claim 6, characterized in that: 6), a high temperature curing structural adhesive film is laid on the contact surface between the rear beam and the skin and the honeycomb core, and a high temperature curing structural filling foam adhesive is laid on the adhesive surface between the rear beam and the honeycomb core.

8. The method according to claim 7, characterized in that: 8), a non-porous isolation film and a breathable felt are sequentially laid on the outer surface of the wedge-shaped trailing edge; the breathable felts are arranged at intervals, and a position is established to lay glass cloth; Use vacuum bag packaging and evacuate to 0.03MPa; Install the fixing board at the location where the glass cloth is laid.

9. The method according to claim 8, characterized in that: 9), vacuum pre-compression is as follows: continue to evacuate the vacuum bag to above 0.095MPa, cold pump and maintain pressure for 60min; Check whether the gap between the lower end of the skin honeycomb assembly and the contact part of the limit block is uniform and less than 2mm; if so, the test is qualified.

10. The method according to claim 9, characterized in that: 10), the curing system is as follows: Heat and pressurize the tank at a maximum heating rate of 1.5℃ / min. The tank pressure reaches 0.20MPa~0.23MPa before the temperature reaches 60℃. Continue to heat to 180℃±5℃ under pressure and keep warm for 120min~180min. Finally, cool down to below 60℃ at a maximum cooling rate of 1.5℃ / min, release the pressure and take the tank out.

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