CN115609954A - A method for forming cone section of tail skirt honeycomb sandwich structure - Google Patents

Abstract

A method for forming a cone segment of a tail skirt honeycomb sandwich structure, comprising the steps of: 1. Designing the inner skin forming tool as a male mold tool, the outer skin forming tool as a female mold tool, and the tail skirt honeycomb sandwich structure forming tool as "zero expansion"Mold; 2. Prepare the inner skin and outer skin, and cut the honeycomb core to the splicing size; 3. The inner surface of the inner skin is attached to the tail skirt honeycomb sandwich structure forming tooling, and the outer surface is attached to the honeycomb core; 4. The inner surface of the outer skin and the The honeycomb core is tested and fitted to determine the position of the outer skin positioning embedded parts; the positioning embedded parts are bonded and cured to the inner skin; the upper and lower sides of the inner skin are installed with retaining bars; Skin and honeycomb lamination 6. The product is packaged and transferred to an autoclave; 7. The product is cured, out of the tank, and demoulded; the radius of the cone section of the tail skirt honeycomb sandwich structure formed by this method is within the range of 1000mm to 5000mm, and the total height size is different. It is larger than 2000mm, and the wall thickness is in the range of 10-100mm, which solves the overall molding problem of the composite material structure of the butt joint of the optical cabin.

Description

A method for forming cone section of tail skirt honeycomb sandwich structure

technical field

The invention relates to a super-large size, high-precision, high-stability honeycomb interlayer cone section forming process, which belongs to the field of manned spaceflight structure systems.

Background technique

The Sky Survey Space Telescope, referred to as the "Optical Module", is the largest space astronomical infrastructure in China so far. It flies in co-orbit with the space station and will provide Chinese scientists with a powerful tool for observing the sky. Among them, the honeycomb sandwich structure of the tail skirt of the optical cabin is the largest composite material cabin structure of the model currently being researched by the Fifth Academy. This cabin provides the interface for rocket docking, and needs to carry out static test assessment with a maximum load of 160t.

At present, the diameter of the rocket docking cabin section commonly used in China is 1215mm, and the diameter of the docking section that needs to be provided by the honeycomb sandwich structure of the tail skirt is 4126mm, which is 3.4 times the diameter of the conventional interface, and the load capacity is 4 times that of the conventional interface. The product and the docking frame are still in the form of docking, and the product has the same cone (circle) requirements as conventional products, which are not greater than 3mm. The large-size molding adopts the conventional female molding method, and the size of the tooling is huge. There is no autoclave equipment that meets the requirements in Beijing for curing. The conventional molding method currently divides the inner and outer skins evenly, and the load capacity cannot meet the design index requirements. Due to the large load capacity and high precision requirements, limited by the size of the equipment, traditional methods cannot be used for forming. It is urgent to develop a new method with small tooling size, high mechanical strength and high surface accuracy.

Contents of the invention

The technical problem of the present invention is: to overcome the deficiencies of the prior art, to provide a method for forming the cone section of the tail skirt honeycomb sandwich structure with "zero expansion" of the inner skin male mold forming and forming tooling, which meets the requirements of the tail skirt honeycomb sandwich structure products The radius of the cone section is within the range of 1000mm to 5000mm, the total height is not greater than 2000mm, and the forming requirements of the wall thickness are within the range of 10 to 100mm.

Technical solution of the present invention is:

A method for forming a cone section of a tail skirt honeycomb sandwich structure, the steps are as follows:

1. According to the product profile of the honeycomb sandwich structure of the tail skirt, the inner skin molding tool is prepared as a male mold tool, the outer skin molding tool is a female mold tool, and the tail skirt honeycomb sandwich structure molding tool is prepared as a "zero expansion" mold;

2. Use the inner skin forming tool to prepare the inner skin, use the outer skin forming tool to prepare the outer skin and paste the release paper, place the positioning embedded parts in the preset processing technology area on the upper and lower sides of the outer skin center, according to the tail skirt The shape and curvature of the honeycomb sandwich structure, determine the splicing size of the honeycomb core and cut it;

3. Attach the inner surface of the inner skin to the outer side of the forming tooling of the honeycomb sandwich structure of the tail skirt, polish, clean and dry the inner skin; brush the primer on the outer surface of the inner skin, apply the adhesive film, and fit the cut honeycomb core;

4. Brush the primer on the inner surface of the outer skin, stick the adhesive film, do not remove the release paper, and make a trial fit with the honeycomb core in step 3 to ensure that the outer skin is evenly distributed, and determine the position of the outer skin positioning embedded parts ; The outer skin positioning embedded parts are bonded and cured to the inner skin, and the upper and lower sides of the inner skin are installed with retaining strips;

5. Remove the release paper of the outer skin, and use the outer skin to position the embedded parts to realize the bonding of the outer skin and the honeycomb;

6. Lay isolation material, air guide material and vacuum bag film on the outer surface of the outer skin in sequence from the inside to the outside, arrange the air suction nozzle and thermocouple, and carry out product packaging; then transfer to the autoclave, and place the product in the designated position good;

7. Product curing, out of the can, demoulding, and testing of product indicators.

Further, the inner skin forming tool is designed and prepared by the following method:

S1. Using python thermodynamic dynamic simulation to simulate the actual position of the inner skin male tooling in the autoclave, according to the distribution of the temperature field in the autoclave, set the inner skin male tooling to achieve the preset high temperature molding Theoretical requirements profile;

S2. The theoretically required profile reached during high-temperature molding is again used in python thermodynamic dynamic simulation to simulate the final required theoretical profile when the temperature is lowered to room temperature, and the inner skin is processed and formed using this profile.

Further, the upper and lower sides of the inner skin forming tooling in the step 1 are evenly staggered, and 4 to 8 air guide channels are reserved respectively.

Further, the forming tooling of the honeycomb sandwich structure of the tail skirt in the first step adopts the form of the split-dimensional shape of the cone segment and the bottom plate of the carbon fiber honeycomb sandwich structure to achieve "zero expansion"; including the connecting ring, the upper bar of the M piece, and the N piece Tail skirt component molding die, M piece lower bar, 2P piece bottom plate connecting plate, P piece bottom plate, and 2P piece bottom plate connecting strip; M>1, N>1, P>1; the assembly of the tail skirt honeycomb sandwich structure forming tooling The method is:

S1. The upper side of the forming mold of the N-piece tail skirt component is connected through the connecting ring, and the lower side is connected through the bottom plate, providing a dimension surface for the formation of the honeycomb sandwich structure of the tail skirt;

S2. The P base plates are connected by 2P base plate connecting plates and 2P base plate connecting strips, wherein: the upper side of every two base plates is connected by 2 base plate connecting plates, and each base plate connecting plate and the base plate are tightened by screws. The connection is realized in the form of fixing and positioning of at least 4 pins, and the connection between each bottom plate connecting strip and the bottom plate is realized by screw fastening, so as to avoid the situation that the bottom plate is opened under the force of “eight”;

S3. The upper retaining strip and the lower retaining strip adopt conical surface retaining strips to fix the upper and lower sides of the honeycomb sandwich structure of the tail skirt; the upper retaining strip is installed on the upper edge of the inner skin, corresponding to the top of the outer skin, and the lower retaining strip is installed The lower edge of the inner skin corresponds to the bottom of the outer skin, and the retaining strip is fixed by physical bonding materials.

Further, the connecting ring is made of steel, the forming mold of the tail skirt component is made of cast steel, the connecting plate of the bottom plate, the bottom plate, and the connecting strip of the bottom plate are made of carbon-skinned honeycomb sandwich structure plates, the upper bar and the lower Barriers are made of aluminum.

Further, the preparation of the inner skin in the step 2 adopts integral molding, and the preparation of the outer skin adopts split molding.

Further, define the 0° layup orientation as the direction of the generatrix of the cone section of the tail skirt honeycomb sandwich structure, and the layup sequence when preparing the inner skin in step 2 is: 0°, 45°, -45°, 90°; 0°, The 45° and -45° lay-ups are made of prepregs with a width of 40mm to 60mm, and the gaps are filled with materials, and the 90° layups are made of narrow strips with a width of 10mm to 30mm.

Further, the preset processing technology area of the outer skin in the step 2 is at the middle position of the inner upper and lower edges of each outer skin.

Further, the steps of fitting the outer skin and the honeycomb core in step 4 include:

S1. Lay isolation material, air guide material and vacuum bag film on the outer surface of the outer skin in order from the inside to the outside to form a vacuum device, and fasten the outer skin and the honeycomb core by vacuuming at room temperature;

S2. Turn on the vacuum device set in step S1, remove the outer skin, check the bonding state of the honeycomb, perform straightening treatment on the non-uniform bonding of the honeycomb and the partial collapse of the honeycomb core, and complete the trial fitting of the outer skin.

Further, during the curing process of the product in step 7, the temperature rise curve is monitored to ensure that the temperature difference of the product is not greater than 5°C.

The beneficial effect of the present invention compared with prior art is:

(1) The present invention realizes the overall molding of the large-scale tail skirt honeycomb sandwich structure through the male mold of the tail skirt honeycomb sandwich structure. Compared with the use of the female mold, the size of the mold is greatly reduced, and the prepared tail skirt honeycomb sandwich structure has a taper of 1.6mm , which is 3mm better than the design index; the taper of the product is controllable, and the applicable cone radius is in the range of R1000mm-R5000mm, the total height is not more than 2000mm, and the wall thickness is in the range of 10-100mm.

(2) The "zero-expansion" mold used in the present invention solves the difficult problem that the normal temperature of the product fits the mold surface, and the dimension of the mold surface cannot be guaranteed after the high-temperature expansion surface expands.

(3) The invention innovatively uses the inner skin as the surface providing surface and packaging surface for product molding, which solves the problem that the mold must be integrally or integrally spliced for sealing.

(4) When the present invention is designing the male mold tooling of the inner skin, the taper angle of the male mold is compensated through mechanical simulation, scientifically considering the expansion of the mold and the situation in the hot pressure field, and rationally optimizing the process design accordingly, providing The accuracy of composite molding is improved.

Description of drawings

Figure 1 is the structure diagram of the honeycomb sandwich of the tail skirt

Figure 2 shows the process flow of forming the honeycomb sandwich structure of the tail skirt

Fig. 3 is the schematic diagram of the inner skin forming tooling of the tail skirt honeycomb sandwich structure of the present invention

Fig. 4 is the schematic diagram of the outer skin forming tooling of the tail skirt honeycomb sandwich structure of the present invention

Fig. 5 is a schematic diagram of the forming tooling of the tail skirt honeycomb sandwich structure of the present invention

Fig. 6 is the front view of the tail skirt honeycomb sandwich structure forming tooling of the present invention

Fig. 7 is a cross-sectional view of the molding tooling of the tail skirt honeycomb sandwich structure of the present invention

Figure 8 is a bottom view of the tail skirt honeycomb sandwich structure forming tooling of the present invention

detailed description

Specific embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings.

As shown in Figure 1, the taper of the honeycomb sandwich structure of the tail skirt of the optical cabin formed by the method of the present invention is better than 2mm; the structural dimensions of the conical segment rotator that can be formed include: the radius of the conical segment is in the range of 1000mm to 5000mm, and the total height is not greater than 2000mm , Wall thickness in the range of 10 ~ 100mm.

Fig. 2 is the process method for forming the cone section of the tail skirt honeycomb sandwich structure of the present invention, comprising the following steps:

Step 1: Determine the product molding process plan according to the configuration of the honeycomb sandwich structure of the tail skirt. The inner skin is formed by an integral male mold, the outer skin is split by a female mold, and the honeycomb sandwich structure adopts a "zero expansion" male mold;

Step 2: Carry out mechanical simulation according to the product profile of the honeycomb sandwich structure of the tail skirt, determine the cone angle of the inner skin mold forming, and design the inner skin forming tooling;

The specific method is: the taper angle of the male mold is simulated by python thermodynamic dynamic simulation, and the actual position of the inner skin male mold tooling in the autoclave is simulated through the mechanical simulation, and the inner skin male mold tooling is set according to the distribution of the temperature field in the autoclave. The theoretically required profile of the mold tooling during high-temperature molding, through mechanical simulation, the profile obtained when the temperature is lowered to normal temperature is determined as the required theoretical profile, and this profile is used to face the inner skin Carry out processing and molding.

Step 3: According to the formulated process plan and the designed inner skin tooling, the inner skin is formed, and the 0° layer orientation is defined as the direction of the generatrix of the cone section of the tail skirt honeycomb sandwich structure. The layering sequence when preparing the inner skin is: 0°, 45°, -45°, 90°;, 0°, 45°, -45° layups are made of 50mm wide prepregs, and the gaps are filled with materials; 90° layups are made of 20mm wide narrow strips ;

Step 4: According to the product profile of the honeycomb sandwich structure of the tail skirt, the outer skin forming tooling design is carried out;

Step 5: According to the formulated process plan and the designed outer skin tooling, the outer skin is formed, and the layer of the outer skin is the same as that of the inner skin;

Step 6: According to the product profile of the tail skirt honeycomb sandwich structure, design the "zero expansion" molding tooling of the product, and use the form of the cone section split dimension shape and the carbon fiber honeycomb sandwich structure bottom plate to achieve "zero expansion". The tooling includes Connecting ring 1, 36 pieces of upper retaining strips 2, 16 pieces of tail skirt component molding dies 3, 36 pieces of lower retaining strips 4, 8 pieces of bottom plate connecting plates 5, 4 pieces of bottom plates 6, and 8 pieces of bottom plate connecting strips 7;

Step 7: Complete the assembly and surface treatment of the honeycomb sandwich structure forming tooling for the tail skirt. The specific assembly process of the tooling is as follows:

The upper side of the 16 tail skirt component molding dies is connected by a connecting ring, and the connecting ring 1 and the tail skirt component molding die 3 are connected by pins and screws; the lower side is connected by a bottom plate 6, and the bottom plate 6 is connected to each tail skirt Component molding dies 3 are connected by pins and screws; 4 base plates 6 are connected by 8 base plate connecting plates 5 and 8 base plate connecting strips 7; among them, the upper side of every two base plates 6 is connected by 2 base plates The boards 5 are connected, and the connection between each bottom board connecting board 5 and the bottom board 6 is realized by screw fastening and at least 4 pin positioning, and the connection between each bottom board connecting strip 7 and the bottom board 6 is realized by screw fastening , to avoid the opening of the "eight" character under the force of the bottom plate; the bottom plate 6 realizes small-area contact with the 16 tail skirt component forming molds 3 through reserved bosses on both sides;

The material of the tooling is as follows:

The connecting ring 1 is made of steel, the tail skirt component molding die 3 is made of cast steel, the bottom plate connecting plate 5, the bottom plate 6, and the bottom plate connecting bar 7 are made of carbon-skinned honeycomb sandwich structure plates, and the upper bar 2 and the lower bar 4 are all made of Aluminum material.

The principle of use of tooling:

The outer side of the 16 tail skirt component forming molds 3 provides the dimension surface for the formation of the honeycomb sandwich structure of the tail skirt, and the upper bar 2 and the lower bar 4 are used for fixing the upper and lower sides of the honeycomb sandwich structure of the tail skirt;

Surface treatment of tooling:

The 16 pieces of tail skirt component molding die 3 need to be degreased at high temperature and wiped clean with solvent before use;

Step 8: Match and install the inner skin of the product formed in step 2 with the forming tooling of the honeycomb sandwich structure of the tail skirt;

Step 9: Surface grinding, solvent wiping and drying the inner skin of the product formed in step 2;

Step 10: According to the shape and curvature of the product, determine the splicing size of the honeycomb core, cut the honeycomb core to the required size, and cut the honeycomb into a trapezoid that can fit better with the mold;

Step 11: Brush primer on the surface of the inner skin of the product processed in step 9, and stick the film;

Step 12: Lay the honeycomb core cut in step 10 with the inner skin according to the process design;

Step 13: Brush the surface of the outer skin formed in step 4 with primer, and stick the film without removing the release paper;

Step 14: Fit the outer skin treated in step 13 with the honeycomb core that has been pasted in step 12 to ensure that the outer skin is evenly distributed, and at the same time determine the position of the outer skin positioning embedded parts;

Step 15: Use room temperature adhesive to bond and fix the positioning embedded parts of the outer skin with the inner skin;

Step 16: Use step 15 to paste the outer skin and position the embedded part at the upper and lower center positions of the outer skin, which can fully ensure the extension of the outer skin and the fit with the honeycomb;

Step 17: Lay isolation material, air guide material and vacuum bag film on the outer surface of the product that has been processed in step 16, and use room temperature vacuuming to achieve a good fit between the outer skin and the product.

Step 18: Turn on the vacuum device made in step 17, remove the auxiliary materials and remove the outer skin, check the state of honeycomb bonding, and correct the unfavorable honeycomb bonding and the partial collapse of the honeycomb;

Step 19: According to the size and position of the outer skin, install the retaining strips on the upper and lower sides of the inner skin. The retaining strips are designed conical surface retaining strips, and the retaining strips are fixed by physical bonding materials;

Step 20: Remove the outer skin isolation material removed in step 18, and then use the outer skin positioning block to achieve a good fit between the outer skin and the honeycomb;

Step 21: Place the isolation material, air guide material and vacuum bag film on the outer surface of the product in step 20 in sequence, and arrange the air suction nozzle and thermocouple according to the process design, and place the air suction nozzle on the side of the product on the product 4 1, 4 are placed on the product side of the lower bar, and the air nozzles are evenly distributed and staggered up and down;

Step 22: Transfer the product in step 21 to the autoclave, and place the product in the designated position according to the process design requirements;

Step 23: The product in step 22 is cured according to the set curing system, and the temperature rise curve is monitored during the process to ensure that the temperature difference between the products is not greater than 5°C. Place a thermocouple on the upper and lower sides of the product tank door. Place one on the upper edge of the side, and one on the top and bottom of the opposite side of the tank door;

Step 24: The product cured in step 23 is taken out of the can, demoulded, corrected, and the physical index detection, non-destructive test and mechanical test piece test of the product are carried out.

Example 1:

When developing the honeycomb sandwich structure of the tail skirt shown in Figure 1, the product molding plan is first determined. The inner skin is formed by a whole male mold, the outer skin is split by a female mold, and the honeycomb sandwich structure uses a "zero expansion" mold. The process simulation of the mold is carried out according to the product size, and the final size of the mold is determined according to the simulation results and engineering experience.

As shown in Figure 3, Figure 4, and Figure 5, the inner skin forming tool, the outer skin forming tool, and the tail skirt sandwich structure forming tool are processed respectively. After the mold is processed, the casting mold or some casting mold parts are degreased and solvent wiped, and the non-cast parts are only wiped. According to the formulated process plan and the designed skin tooling, the inner and outer skins are respectively formed, and the 0° layer orientation is defined as the direction of the generatrix of the cone section of the tail skirt honeycomb sandwich structure. The layering sequence when preparing the inner and outer skins is: : 0°, 45°, -45°, 90°; 0°, 45°, -45° use prepregs with a width of 50mm, and fill the gaps; 90° layups use 20mm width narrow strips Make layers.

During the product curing process, the ventilation channel is designed, and the product package is cured and formed. Die assembly is carried out according to the forming tooling drawings of the honeycomb sandwich structure of the tail skirt.

As shown in Figures 6 to 8: the upper side of the molding dies of the 16 tail skirt components 3 is connected through the connecting ring 1, and the connecting ring 1 and the molding dies of the tail skirt components 3 are connected by pins and screws; the lower side is connected through the bottom plate 6 To connect, the base plate 6 is connected with each tail skirt component molding die 3 by pins and screws; 4 base plates 6 are connected by 8 base plate connecting plates 5 and 8 base plate connecting strips 7; Leave the boss to realize the small-area contact with 16 tail skirt assembly molding dies 3.

After the mold assembly is completed, the inner skin is matched with the tail skirt honeycomb sandwich structure forming tooling. After the trial assembly, the inner skin of the product is surface polished, solvent wiped and dried. According to the shape and curvature of the product, the splicing size of the honeycomb core is determined, and the honeycomb core is cut to the required size, and the honeycomb is cut into a trapezoid that can fit better with the mold. Brush the primer on the surface of the formed outer skin, stick the adhesive film, and do not remove the release paper, and test fit the outer skin and the honeycomb core to ensure that the outer skin is evenly distributed, and at the same time determine the position of the outer skin positioning embedded parts Location.

The positioning embedded parts of the outer skin are bonded and fixed to the inner skin with room temperature adhesive. By pasting the outer skin and positioning the embedded part at the upper and lower center positions of the outer skin, the extension of the outer skin and the fit with the honeycomb can be fully guaranteed. The outer surface of the product that has been processed is laid with isolation material, air-conducting material and vacuum bag film in sequence, and the outer skin and the product are well bonded by vacuuming at room temperature.

After removing the auxiliary materials, take off the outer skin, check the state of the honeycomb bonding, and correct the unfavorable honeycomb bonding and the partial collapse of the honeycomb. According to the size and position of the outer skin, the upper and lower sides of the inner skin are equipped with retaining strips. The retaining strips are designed conical surface retaining strips, and the retaining strips are fixed by physical bonding materials.

Remove the removed outer skin isolation material, and then use the outer skin positioning block to achieve a good fit between the outer skin and the honeycomb. Lay isolation material, air guide material and vacuum bag film on the outer surface of the product in sequence, and arrange air suction nozzles and thermocouples according to the process design. Place 4 suction nozzles on the product side of the upper bar of the product, and place 4 on the product side of the lower bar. 1, the air nozzles are evenly distributed and staggered up and down. Transfer the product to the autoclave, and place the product in the designated position according to the process design requirements.

The product is cured according to the set curing system, and the temperature rise curve is monitored during the process to ensure that the temperature difference between the products is not greater than 5°C. One thermocouple is placed on the upper and lower sides of the product tank door, and one is placed on the upper and lower sides of the tank door. One, place one on the upper edge of the side in the middle of the product tank door and the opposite side of the tank door, take the cured product out of the tank, demould, correct it, and perform physical index detection, non-destructive testing and mechanical test piece testing of the product .

The tail skirt honeycomb sandwich structure forming tooling proposed in the present invention has the following advantages:

(a) The tail skirt honeycomb sandwich structure forming tooling of the present invention can directly form the tail skirt honeycomb sandwich structure. The inner skin of the structure is integrally formed, the structure strength is high, and it can withstand 160 tons of static test assessment.

(b) The "zero-expansion" mold used in the present invention solves the problem that the normal temperature of the product fits the surface of the mold, and the size of the mold surface cannot be guaranteed after the high-temperature expansion surface expands.

(c) The present invention uses ordinary steel material as the main body of the mold to realize the problem of "zero expansion" of the mold. The ingenious design increases the inner skin, and the product is solidified and encapsulated in the inner skin. It ingeniously resolved the problem that the tooling should not only meet the airtightness requirements but also achieve "zero expansion".

(d) During the design process of the tooling of the present invention, sufficient process simulation calculations have been carried out, the expansion of the mold and the situation in the hot-pressing field have been scientifically considered, and the reasonable optimization of the process design has been carried out accordingly to provide the accuracy of composite material forming.

(e) The inner skin of the present invention adopts a positive mold design. In order to reduce the machining workload of the mold, no glue guide groove is added to the machine. Based on the research on the characteristics of the resin, an aluminum liner with holes is designed to solve the air guide problem when the inner skin is solidified.

The content that is not described in detail in the specification of the present invention belongs to the well-known technology of those skilled in the art. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention, and any person skilled in the art can use the methods disclosed above and technical content to analyze the present invention without departing from the spirit and scope of the present invention. Possible changes and modifications are made in the technical solution. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention, which do not depart from the content of the technical solution of the present invention, all belong to the technical solution of the present invention. protected range.

Claims (10)

1. A tail skirt honeycomb sandwich structure conical section forming process method is characterized in that a product is a tail skirt honeycomb sandwich structure and comprises an inner skin, an outer skin and a honeycomb core, wherein the honeycomb core is stuck to the outer surface of the inner skin, and the inner skin is arranged outside the honeycomb core; the method is characterized by comprising the following steps:

1. preparing an inner skin forming tool as a male die tool, an outer skin forming tool as a female die tool and a tail skirt honeycomb sandwich structure forming tool as a zero-expansion die according to the product molded surface of the tail skirt honeycomb sandwich structure;

2. preparing an inner skin by using an inner skin forming tool, preparing an outer skin by using an outer skin forming tool, adhering release paper, placing positioning embedded parts in processing process areas preset on the upper side and the lower side of the middle position of the outer skin, determining the splicing size of the honeycomb core according to the profile and the curvature of the tail skirt honeycomb sandwich structure, and cutting;

3. the inner surface of the inner skin is attached to the outer side of the tail skirt honeycomb sandwich structure forming tool, and the inner skin is polished, cleaned and dried; brushing base glue on the outer surface of the inner skin, sticking a glue film, and sticking the cut honeycomb core;

4. brushing primer on the inner surface of the outer skin, pasting an adhesive film, not removing release paper, trial assembling and pasting with the honeycomb core obtained in the third step, ensuring that the outer skin is uniformly distributed, and determining the position of the outer skin for positioning the embedded part; the outer skin positioning embedded part is bonded and solidified with the inner skin, and the upper side and the lower side of the inner skin are provided with barrier strips;

5. removing the outer skin release paper, and positioning the embedded part by using the outer skin to realize the attachment of the outer skin and the honeycomb;

6. sequentially laying an isolation material, an air guide material and a vacuum bag film on the outer surface of the outer skin from inside to outside, arranging an air suction nozzle and a thermocouple, and packaging the product; then transferring the product to an autoclave, and placing the product at a specified position;

7. and (5) solidifying the product, taking out of the tank, demolding, and testing the product index.

2. The forming process method for the tapered section of the honeycomb sandwich structure with the tail skirt according to claim 1, is characterized in that: the inner skin forming tool is designed and prepared by the following method:

s1, simulating an actual position of an inner skin male die tool placed in an autoclave by adopting python thermodynamic dynamic simulation, and setting a theoretical required profile of the inner skin male die tool which is achieved during preset high-temperature forming according to the distribution condition of a temperature field in the autoclave;

and S2, cooling the theoretical required profile achieved in high-temperature forming to normal temperature by using python thermodynamic dynamic simulation again to obtain the final required theoretical profile, and machining and forming the inner skin by using the profile.

3. The forming process method for the tapered section of the honeycomb sandwich structure with the tail skirt according to claim 1, is characterized in that: and 4-8 air guide channels are uniformly reserved on the upper side and the lower side of the inner skin forming tool in the first step in a staggered manner.

4. The forming process method for the tapered section of the honeycomb sandwich structure with the tail skirt according to claim 1, is characterized in that: the tail skirt honeycomb sandwich structure forming tool in the first step adopts a mode that a conical section split dimensional profile is matched with a carbon fiber honeycomb sandwich structure bottom plate to realize zero expansion; the forming die comprises a connecting ring (1), M upper baffle strips (2), N tail skirt component forming dies (3), M lower baffle strips (4), 2P bottom plate connecting plates (5), P bottom plates (6) and 2P bottom plate connecting strips (7); m >1, N > < 1, P > < 1; the assembly method of the forming tool for the honeycomb sandwich structure of the tail skirt comprises the following steps:

s1, the upper sides of N tail skirt assembly forming dies (3) are connected through a connecting ring (1), and the lower sides are connected through a bottom plate (6) to provide a dimensional surface formed by a tail skirt honeycomb sandwich structure;

s2, P piece bottom plate (6) are connected through 2P piece bottom plate connecting plate (5) and 2P piece bottom plate connecting strip (7), wherein: the upper side of the splicing part of every two bottom plates (6) is connected by 2 bottom plate connecting plates (5), each bottom plate connecting plate (5) is connected with the bottom plate (6) in a screw fastening and at least 4 pin positioning mode, each bottom plate connecting strip (7) is connected with the bottom plate (6) in a screw fastening mode, and the condition that the bottom plate is stressed and splayed is avoided;

s3, fixing the upper side and the lower side of the honeycomb sandwich structure of the tail skirt by adopting conical surface barrier strips for the upper barrier strip (2) and the lower barrier strip (4); the upper barrier strip (2) is arranged on the upper edge of the inner skin and corresponds to the top end of the outer skin, the lower barrier strip (4) is arranged on the lower edge of the inner skin and corresponds to the bottom end of the outer skin, and the barrier strips are fixed through a physical adhesive material.

5. The forming process method for the tail skirt honeycomb sandwich structure conical section according to claim 4, is characterized in that: the connecting ring (1) is made of steel, the tail skirt assembly forming die (3) is made of cast steel, the bottom plate connecting plate (5), the bottom plate (6) and the bottom plate connecting strip (7) are made of carbon skin honeycomb sandwich structure plates, and the upper retaining strip (2) and the lower retaining strip (4) are made of aluminum.

6. The forming process method for the tapered section of the honeycomb sandwich structure with the tail skirt according to claim 1, is characterized in that: and step two, preparing the inner skin, integrally forming, and preparing the outer skin, and split-forming.

7. The forming process method for the tapered section of the honeycomb sandwich structure with the tail skirt according to claim 1, is characterized in that: defining a 0-degree paving position as the direction of a taper section bus of the tail skirt honeycomb sandwich structure, wherein the paving sequence when the inner skin is prepared in the second step is as follows: 0 °, 45 °, -45 °,90 °; the 0 degree, 45 degree and 45 degree layers are made by prepreg with the width of 40 mm-60 mm and the gap material is supplemented, and the 90 degree layers are made by narrow strips with the width of 10 mm-30 mm.

8. The process method for molding the tapered section of the honeycomb sandwich structure of the tail skirt according to claim 1, wherein the process method comprises the following steps: and the processing process area preset by the outer skin is arranged in the middle of the upper edge and the lower edge of the inner side of each outer skin.

9. The forming process method for the tapered section of the honeycomb sandwich structure with the tail skirt according to claim 1, is characterized in that: the step four of trial fitting and fitting the outer skin and the honeycomb core comprises the following steps of:

s1, sequentially laying an isolation material, an air guide material and a vacuum bag film on the outer surface of an outer skin from inside to outside to form a vacuum device, and fastening the outer skin and a honeycomb core by adopting a normal-temperature vacuumizing mode;

and S2, opening the vacuum device arranged in the step S1, taking down the outer skin, checking the bonding state of the honeycomb, and carrying out straightening treatment on the part where the honeycomb is not uniformly bonded and the local collapsed edge of the honeycomb core to finish the trial assembly bonding of the outer skin.

10. The forming process method for the tapered section of the honeycomb sandwich structure with the tail skirt according to claim 1, is characterized in that: and seventhly, monitoring a temperature rising curve in the product curing process to ensure that the temperature difference of each part of the product is not more than 5 ℃.

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