Molding tool and method for annular rib co-curing structure of air inlet channel of aircraft

Abstract

The invention discloses a forming tool and method for an annular rib co-curing structure of an aircraft air inlet channel, and belongs to the technical field of aviation composite material forming. The manufacturing cost can be effectively reduced, and the weight of the air inlet duct of the aircraft can be reduced. The forming tool comprises a soft mold paving mold, an air inlet channel main body paving mold, a paving platform, a soft mold positioner and an air inlet channel demolding tool. According to the air inlet duct, the nine annular T-shaped reinforcing ribs of the air inlet duct main body piece can be integrally formed, the manufacturing cost can be effectively reduced, and the weight of the air inlet duct of the aircraft can be reduced. By means of the soft mold positioner, the problem that the operation space is limited in the paving process is solved, and meanwhile it is guaranteed that the position tolerance after the nine annular T-shaped reinforcing ribs and the air inlet channel body are integrally formed is within + / -0.5 mm. The paving platform is ingeniously designed to have three functions, namely a rotary paving function, a positioning function of a soft mold by being combined with a soft mold positioner and a bracket function of curing in a tank.

Description

Technical Field

[0001] The invention belongs to the technical field of aviation composite material molding, and in particular relates to a molding tool and method for a co-cured structure of an aircraft air inlet annular rib. Background Art

[0002] With the advancement of materials science and technology, in the field of composite materials, the shapes and structures of composite parts are becoming more diverse and complex. The design and manufacturing technology of the air intake duct is also constantly improving and innovating. By optimizing the shape and structure of the air intake duct, the intake efficiency and combustion efficiency are further improved. The composite structural parts of the air intake duct that have emerged have also begun to become more diverse and complex. In view of the current reality, in order to adapt to the development of the times, technical personnel in this field need to develop and mold these diverse and complex composite parts.

[0003] Among the composite parts of aircraft, there is a typical structure with a "U"-shaped structure in cross-section and longitudinal section, and 9 annular T-shaped reinforcement ribs on the inner side of the air inlet body. The traditional forming method of this part is to connect the reinforcement ribs and the air inlet body by riveting. This method not only has high manufacturing cost but also has a great impact on the weight of the aircraft. Summary of the invention

[0004] The object of the present invention is to provide a molding tool and method for a co-cured structure of an annular rib of an aircraft air inlet, which can effectively reduce the manufacturing cost and reduce the weight of the aircraft air inlet.

[0005] The technical solution adopted by the present invention is:

[0006] A molding tool for an aircraft air inlet annular rib co-curing structure, comprising

[0007] Soft mold paving mold, used for paving and forming soft mold;

[0008] The air intake duct main body paving mold is used for paving and forming the air intake duct main body;

[0009] A paving platform is used to support the paving mold of the air intake duct body;

[0010] The soft mold positioner is installed on the laying platform to assist in laying the soft mold on the main body of the air intake to form annular T-shaped reinforcement ribs;

[0011] The air intake duct demoulding tool is used to support the air intake duct main body paving mold that needs to be removed.

[0012] A method for forming an aircraft air inlet annular rib co-curing structure comprises the following steps:

[0013] S1. Use a soft mold to lay a soft mold;

[0014] S2. Assemble the main body of the air intake duct;

[0015] S3. The assembled air intake main body paving mold is hoisted to the paving platform;

[0016] S4. Lay the main body of the air intake duct;

[0017] S5. Install the soft mold locator;

[0018] S6. Lay the annular T-shaped reinforcement;

[0019] S7. The soft mold positioner retracts to make a cylindrical vacuum bag, and the soft mold positioner extends forward to position outside the bag;

[0020] S8. Put into the can for curing and demoulding.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention can achieve an overall size of 2850mmX1500mmX1050mm for the air inlet main body, a "U"-shaped structure in the transverse and longitudinal sections, and an integral molding with 9 annular T-shaped reinforcing ribs, which can effectively reduce the manufacturing cost and also reduce the weight of the aircraft air inlet.

[0023] 2. The retractable soft mold positioner in the present invention not only solves the problem of limited operating space during paving, but also ensures that the position tolerance of the 9 annular T-shaped reinforcement ribs and the air inlet duct body after integral molding is within ±0.5mm.

[0024] 3. The present invention cleverly designs the paving platform to have three effects and one function: one is the rotating paving function; the second is the combination with the soft mold positioner to realize the positioning function of the soft mold; the third is the bracket function to realize the curing in the tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is an axonometric view of the present invention;

[0026] Figure 2 It is a schematic diagram of the structure of the soft mold paving mold of the present invention;

[0027] Figure 3 It is a schematic diagram of the structure of the air inlet demoulding tooling of the present invention;

[0028] Figure 4 15 is a schematic diagram of the structure of the air inlet main body paving mold of the present invention;

[0029] Figure 5 It is a partial schematic diagram of the annular T-shaped reinforcement rib;

[0030] Figure 6 This is a schematic diagram of the process of laying annular T-shaped reinforcement ribs according to the present invention;

[0031] Among them: 1. soft mold; 2. soft mold paving mold; 3. air inlet main body paving mold; 4. paving platform; 5. soft mold positioner; 6. air inlet demoulding tooling; 301. left connecting shaft assembly; 302. left section core mold assembly; 303. middle core mold assembly; 304. right section core mold assembly; 305. right connecting shaft assembly; 401. moving frame; 402. reducer; 403. support seat; 501. support frame; 502. positioning sleeve; 503. positioning rod; 504. positioning plate; 505. square steel. DETAILED DESCRIPTION

[0032] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings.

[0033] If one wants to achieve co-curing and one-piece molding of the air inlet main body and the nine annular T-shaped reinforcement ribs, the key is to prepare a set of tooling that can achieve co-curing and molding of the air inlet main body and the nine annular T-shaped reinforcement ribs.

[0034] like Figure 1 to Figure 5 As shown, the present invention provides a molding tool for a co-cured structure of an annular rib of an aircraft air inlet, comprising

[0035] A soft mold paving mold 2 is used for paving the soft mold 1;

[0036] The air intake duct main body paving mold 3 is used for paving and forming the air intake duct main body;

[0037] The paving platform 4 is used to support the paving mold 3 of the air inlet main body;

[0038] The soft mold positioner 5 is installed on the laying platform 4 and is used to assist in laying the soft mold 1 on the air inlet main body to form an annular T-shaped reinforcement rib;

[0039] The air intake duct demoulding tool 6 is used to support the air intake duct main body paving mold 3 that needs to be removed.

[0040] like Figure 1 , Figure 4 As shown, the air inlet main body paving mold 3 includes a left connecting shaft assembly 301, a left section core mold assembly 302, an intermediate core mold assembly 303, a right section core mold assembly 304 and a right connecting shaft assembly 305 which are connected from left to right in sequence by screw pins; the left connecting shaft assembly 301 and the right connecting shaft assembly 305 are used to connect with the connection interface of the paving platform 4, and the left section core mold assembly 302, the intermediate core mold assembly 303 and the right section core mold assembly 304 are all block connection structures.

[0041] like Figure 1As shown, the paving platform 4 includes a moving frame 401, a reducer 402 and two support seats 403; support seats 403 for fixing the air inlet duct main body paving mold 3 are arranged at both ends of the moving frame 401, and the two support seats 403 are respectively connected to the left connecting shaft assembly 301 and the right connecting shaft assembly 305, and are provided with locking pins every 60° angle. The reducer 402 is installed at one end of the moving frame 401 according to the rotation center of gravity of the air inlet duct main body paving mold 3, and the output end of the reducer 402 is connected to the air inlet duct main body paving mold 3, so as to realize the rotation function of the air inlet duct main body paving mold 3 on the paving platform 4.

[0042] like Figure 1 As shown, the soft mold positioner 5 includes a plurality of support frames 501, a plurality of positioning sleeves 502, a plurality of positioning rods 503 and a plurality of positioning plates 504; the plurality of support frames 501 are arranged side by side on the front and rear sides of the air inlet duct main body paving mold 3, and the support frames 501 on the same side are supported and connected by square steels 505, and each support frame 501 is sequentially installed with positioning sleeves 502 from top to bottom, and a positioning rod 503 is slidably installed in each positioning sleeve 502, and the positioning sleeve 502 and the positioning rod 503 are fixed by a top screw, and the head of each positioning rod 503 is installed by a positioning plate 504, and the positioning plates 504 are all arranged toward the air inlet duct main body paving mold 3.

[0043] Functions to be achieved by the molding tooling: 1. Ensure the contour of the air intake duct body is ±0.3mm. 2. Ensure that the non-destructive testing rate of the molded parts is within 1.5%, requiring no visually visible pores on the surface and no internal stratification. 3. Ensure that the thickness tolerance of the molded parts is the theoretical thickness t±(tX10%), the edge contour size accuracy is ±0.5mm, and the glue-poor area shall not be greater than 10% of the total area. 4. Realize the rotational paving of the air intake duct body; 5. Realize the paving of the annular T-shaped reinforcement ribs and co-curing molding with the air intake duct body, and ensure the position tolerance of the T-shaped reinforcement ribs is ±0.5mm.

[0044] The present invention provides a molding method of an aircraft air inlet annular rib co-curing structure, comprising the following steps:

[0045] Step 1: Use soft mold paving mold 2 to pave soft mold 1. Perform the soft mold paving work according to the ply information table. The ply information table is as follows:

[0046]

[0047] The main function of the soft mold 1 is to fix the 9 annular T-shaped reinforcement ribs to the main body of the air intake duct. According to the configuration characteristics of the 9 annular T-shaped reinforcement ribs, 9 groups of soft molds 1 are manufactured, each group of soft molds 1 is divided into 4 sections, each section is connected with screws, and 0.5mm silicone pads are placed between the sections to ensure that the soft mold 1 is pressurized during the co-curing molding process. The 36-segment soft mold 1 is formed by paving and molding with 36-segment soft mold paving mold 2. Figure 2 shown.

[0048] Step 2: Assemble the air intake duct main body paving mold 3. The overall size of the air intake duct main body is 2850mmX1500mmX1050mm, and the horizontal and vertical sections are "U"-shaped structures. Based on this large-sized "U"-shaped structure component that is difficult to form, the air intake duct main body paving mold 3 is designed as a block connection structure for easy demoulding. The inserts are connected with screws, and the inserts are divided into 3 sections in the axial direction: the left section core mold assembly 302, the middle core mold assembly 303, and the right section core mold assembly 304. In the radial direction, the middle and right section core mold assemblies 304 are divided into 6 pieces according to the order of demoulding, and the left section core mold assembly 302 is divided into 8 pieces. In order to realize the rotational paving of the air intake duct main body, rotating shaft assemblies are set at both ends of the air intake duct main body paving mold 3, which are the left connecting shaft assembly 301 and the right connecting shaft assembly 305, respectively, and the two rotating shafts are used as connection interfaces with the paving platform 4. The assembly of the air intake duct main body paving mold 3 is to first connect the middle core mold assembly 303 into one body, then connect the inserts of the left section core mold assembly 302 and the right section core mold assembly 304 into one body, and then connect the left section core mold assembly 302 and the right section core mold assembly 304 to the middle core mold assembly 303. Finally, the left connecting shaft assembly 301 is connected to one end of the left section core mold assembly 302, and the right connecting shaft assembly 305 is connected to one end of the right section core mold assembly 304. The assembly of the air intake duct main body paving mold is completed.

[0049] Step 3: Lift the assembled air intake main body paving mold 3 to the paving platform 4. There are support seats 403 at both ends of the paving platform 4 to fix the air intake main body paving mold 3. The support seats 403 are connected to the left connecting shaft assembly 301 and the right connecting shaft assembly 305, and are equipped with locking pins every 60°. A reducer 402 is installed at one end of the paving platform 4 according to the rotation center of gravity of the air intake main body paving mold 3 to realize the rotation function of the air intake main body paving mold 3 on the paving platform 4. The paving platform 4 has three effects and one function. One is the function of preparing for rotation paving, the second is to combine with the soft mold positioner 5 to realize the positioning function of the soft mold 1, and the third is to realize the bracket function of the tank curing.

[0050] Step 4: Laying the intake duct body. Move the assembled intake duct body laying mold 3 and the laying platform 4 into the purification room. When the ambient temperature and humidity conditions meet the requirements, lay multiple groups of composite material plies on the outer surface of the intake duct body laying mold 3 as required. The ply sequence of each group of composite material plies is 0°, 45°, 90°, -45°. After laying each group of composite material plies, paste a vacuum bag on the outer surface of this group of composite material plies and apply a negative pressure of -0.06 to -0.1 MPa, and maintain the pressure for 5 - 20 minutes for pre-compaction. Before laying the next group of composite material plies, remove the vacuum bag, and then lay the next group of composite material plies until the laying of the intake duct body semi-finished product is completed.

[0051] Step 5: Install the soft mold positioner 5. First, confirm that the "Z" axis of the intake duct body laying mold 3 is perpendicular to the laying platform 4. Connect each group of soft mold positioners 5 to the laying platform 4 with screw pins. The support frame 501 is a structure of 10 square steel frames, 5 groups on each side, and the 5 groups are supported and connected by square steel 505 in the middle. Arrange telescopic positioners according to the position of the positioning soft mold. 2 groups of telescopic positioners need to be arranged for each half soft mold 1, and a total of 72 groups of telescopic positioners are arranged for 36 sections of soft molds. The telescopic positioners are respectively connected to 10 square steel frames. The telescopic positioner is to ensure the operable space during the laying process of the T-shaped stiffener. The telescopic positioner is composed of a positioning sleeve 502, a positioning rod 503 and a positioning plate 504.

[0052] Step 6: Laying the annular T-shaped stiffener. ① Surround the intake duct body and lay the "one" character part of the character, ② lay the "L" character part on one side of the character. For this side "L" character part, first lay it in the "one" character shape, and then install 4 sections of soft molds 1 according to the position of the soft mold positioner 5 and connect them with screws. Then bend the carbon cloth laid in the "one" character shape to complete the laying of this side "L" character. ③ Finally, lay the "L" character part on the other side. There are a total of 9 annular T-shaped stiffeners. Sequentially carry out the composite material plies of the next annular T-shaped stiffener according to the above method until the laying of 9 annular T-shaped stiffeners is completed. As shown in Figure 5 Figure 5 and Figure 6 shown.

[0053] Step 7: Retract the soft mold positioner 5, make a cylindrical vacuum bag, extend the soft mold positioner 5, and position it outside the bag. Install 2 vacuum nozzles on the left and right connecting shaft components 305 at both ends. One is connected to the air source to apply a negative pressure of -0.085 to -0.1 MPa, and the other is connected to a pressure gauge to monitor the negative pressure value to ensure that there is no air leakage in the vacuum.

[0054] Step 8: Enter the autoclave for curing and demolding.

[0055] Curing process: Place the entire set of molding tooling in the autoclave, connect the vacuum pipeline and thermocouple, and carry out curing. When the pressure in the autoclave is increased to 0.2MPa, maintain the pressure for 5 minutes, and then continue to pressurize; when the positive pressure reaches 0.3MPa, maintain the pressure for 10 minutes, and then continue to pressurize; when the positive pressure reaches 0.9MPa, start to heat up, and the heating rate is 1℃ / min; when the temperature reaches 120℃, keep the temperature and pressure for 120min, and then continue to heat up. When the temperature reaches 180℃, keep the temperature and pressure for 150min, then start to cool down, and the cooling rate is 1℃ / min. When the temperature drops below 80℃ and the pressure drops to 0MPa, open the autoclave, and when the mold temperature drops below 20℃, demoulding is carried out.

[0056] Demolding order:

[0057] 1) Retract the soft mold positioner 5 and remove it from the paving platform 4.

[0058] 2) Remove the vacuum bag.

[0059] 3) Remove the soft mold 1 of the 9 T-shaped reinforcement ribs one by one.

[0060] 4) Remove the air intake duct main body paving mold 3: Use a crane to lift the lifting rings on the left connecting shaft assembly 301 and the right connecting shaft assembly 305 at both ends, transfer the air intake duct main body paving mold 3 to the air intake duct demoulding tooling 6, and remove the left connecting shaft assembly 301, the right connecting shaft assembly 305, the middle insert on the upper part of the left section core mold assembly 302, the middle insert on the upper part of the right section core mold assembly 304, the remaining inserts of the left section core mold assembly 302, the remaining inserts of the right section core mold assembly 304, the middle insert on the upper part of the middle core mold assembly 303, and the remaining inserts of the middle core mold assembly 303. Figure 3 shown.

[0061] 5) Remove the air intake duct body from the air intake duct demoulding tool 6.

[0062] 6) Clean the main composite material parts of the air intake duct and cut the parts along the cutting line. At this point, the preparation of the composite material parts of the air intake duct is completed.

[0063] The molding method can produce an air intake composite material part with annular ribs and an overall size of 2850mmX1500mmX1050mm, which belongs to the composite material structure integrated molding technology.

[0064] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A molding tool for a co-cured structure of an annular rib of an aircraft air inlet, characterized by: include A soft mold paving mold (2) is used for paving the soft mold (1); The air intake duct main body paving mold (3) is used for paving and forming the air intake duct main body; A paving platform (4) is used to support the air intake duct main body paving mold (3); A soft mold positioner (5) is installed on the laying platform (4) and is used to assist in laying the soft mold (1) on the air inlet main body to form an annular T-shaped reinforcement rib; The air intake duct demoulding tool (6) is used to support the air intake duct main body paving mold (3) that needs to be removed.

2. The molding tool for the co-curing structure of the annular rib of an aircraft air inlet according to claim 1, characterized in that: According to the configuration of the annular T-shaped reinforcing ribs, multiple groups of soft molds (1) are manufactured, each group of soft molds (1) is divided into multiple sections, each section of the soft mold (1) is connected by screws, and 0.5 mm silicone pads are placed between the sections.

3. The molding tool for the co-cured structure of the annular rib of an aircraft air inlet according to claim 1, characterized in that: The air inlet main body paving mold (3) comprises a left connecting shaft assembly (301), a left section core mold assembly (302), an intermediate core mold assembly (303), a right section core mold assembly (304) and a right connecting shaft assembly (305) which are connected in sequence from left to right by screw pins; the left connecting shaft assembly (301) and the right connecting shaft assembly (305) are used to connect to the connection interface of the paving platform (4), and the left section core mold assembly (302), the intermediate core mold assembly (303) and the right section core mold assembly (304) are all block connection structures.

4. The molding tool for the co-cured structure of the annular rib of an aircraft air inlet according to claim 1, characterized in that: The paving platform (4) comprises a movable frame (401), a reducer (402) and two support seats (403); support seats (403) for fixing the air intake duct main body paving mold (3) are arranged at both ends of the movable frame (401); the two support seats (403) are respectively connected to the left connecting shaft assembly (301) and the right connecting shaft assembly (305), and are provided with locking pins at every 60° rotation angle; a reducer (402) is installed at one end of the movable frame (401) according to the rotation center of gravity of the air intake duct main body paving mold (3); the output end of the reducer (402) is connected to the air intake duct main body paving mold (3), so as to realize the rotation function of the air intake duct main body paving mold (3) on the paving platform (4).

5. The molding tool for the co-cured structure of the annular rib of an aircraft air inlet according to claim 1, characterized in that: The soft mold positioner (5) includes a plurality of support frames (501), a plurality of positioning sleeves (502), a plurality of positioning rods (503) and a plurality of positioning plates (504); the plurality of support frames (501) are arranged side by side on the front and rear sides of the air inlet duct main body paving mold (3); the support frames (501) on the same side are supported and connected by square steel (505); each support frame (501) is sequentially installed with positioning sleeves (502) from top to bottom; each positioning sleeve (502) is slidably installed with a positioning rod (503); the positioning sleeve (502) and the positioning rod (503) are fixed by a top screw; the head of each positioning rod (503) is installed with a positioning plate (504); and the positioning plates (504) are arranged toward the air inlet duct main body paving mold (3).

6. A molding method using a molding tool for a co-cured structure of an aircraft inlet annular rib according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Using a soft mold to pave the mold (2) to pave the soft mold (1); S2. Assembling the air inlet body paving mold (3); S3. The assembled air inlet main body paving mold (3) is hoisted to the paving platform (4); S4. Lay the main body of the air intake duct; S5. Install the soft mold positioner (5); S6. Lay the annular T-shaped reinforcement; S7. The soft mold positioner retracts to make a cylindrical vacuum bag, and the soft mold positioner extends forward to position outside the bag; S8. Put into the can for curing and demoulding.

7. The method for forming a co-cured structure of an aircraft air inlet annular rib according to claim 6, characterized in that: The specific steps of assembling the air intake duct main body paving mold (3) in S2 are: firstly connect the middle core mold assembly (303) into one body, then respectively connect the inserts of the left section core mold assembly (302) and the right section core mold assembly (304) into one body, then respectively connect the left section core mold assembly (302), the right section core mold assembly (304) and the middle core mold assembly (303), and finally connect the left connecting shaft assembly (301) to one end of the left section core mold assembly (302), and the right connecting shaft assembly (305) to one end of the right section core mold assembly (304), and the air intake duct main body paving mold is assembled.

8. The method for forming a co-cured structure of an aircraft air inlet annular rib according to claim 6, characterized in that: The specific steps of paving the air intake duct body in S4 are as follows: moving the assembled air intake duct body paving mold (3) and the paving platform (4) into the clean room, paving multiple groups of composite material plies on the outer surface of the air intake duct body paving mold (3) as required, the plying order of each group of composite material plies being 0°, 45°, 90°, and -45°, and after paving each group of composite material plies, pasting a vacuum bag on the outer surface of the group of composite material plies and drawing a negative pressure of -0.06 to -0.1 MPa, maintaining the pressure for 5 to 20 minutes for pre-compaction, and before proceeding to the next group of composite material plies, removing the vacuum bag, and then proceeding to the next group of composite material plies, until the paving of the semi-finished air intake duct body is completed.

9. The method for forming a co-cured structure of an aircraft air inlet annular rib according to claim 6, characterized in that: The step of laying the annular T-shaped reinforcement ribs in S6 comprises the following steps: S1. Lay around the intake duct body The "one" part in the shape of " "; S2. Paving The "L"-shaped part on one side of the shape is first laid in an "I" shape, and then a plurality of sections of soft mold (1) are installed according to the position of the soft mold positioner (5) and connected with screws, and then the carbon cloth laid in the "I" shape is bent to complete the "L"-shaped laying on this side; S3. Finally, lay the "L"-shaped part on the other side. There are 9 annular T-shaped reinforcement ribs in total. Follow the above method to lay the next layer of composite material of annular T-shaped reinforcement ribs until the laying of 9 annular T-shaped reinforcement ribs is completed.

10. The method for forming a co-cured structure of an aircraft air inlet annular rib according to claim 6, characterized in that: The operation process of tank curing and demoulding in S8 is as follows: Curing process: Place the entire molding tooling in the autoclave, connect the vacuum pipeline and thermocouple, and perform curing. After curing, demoulding is performed; Demolding order: S801. Retract the soft mold positioner (5) and remove it from the paving platform (4); S802. Remove the vacuum bag; S803. Sequentially remove the soft mold of the 9 T-shaped reinforcement ribs (1); S804. Remove the main paving mold of the air inlet duct (3); S805. Remove the air inlet body from the air inlet demoulding tool (6); S806. Clean the main composite material parts of the air intake duct and cut the parts along the cutting line. At this point, the preparation of the main composite material parts of the air intake duct is completed.

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