A multi-fracture arc-shaped honeycomb sandwich structure curing molding tool and method

Abstract

The present invention relates to a multi-broken arc-shaped honeycomb sandwich structure curing and molding tool and method, and belongs to the technical field of curing and molding of composite honeycomb sandwich structures. The curing and molding tool comprises a molding mold body, a pressure equalizing plate, a positioning block, a positioning pin, a first splicing strip, a second splicing strip, and an edge block; by designing a positioning interface on the molding mold body, using built-in embedded parts to position the molding mold body and the skin, the skin and the honeycomb core are spliced ​​in petals, the splicing position of the folded segments is reinforced by installing splicing strips, and a thinner pressure equalizing plate is used for pressurization. The problem that the built-in metal parts of the arc-shaped curved surface skin extension cannot be accurately positioned is overcome, the overall hole position accuracy of the multi-broken arc-shaped honeycomb sandwich structure is improved, the molding quality at the inflection point of the multi-broken arc-shaped honeycomb sandwich structure is effectively guaranteed, and the risk of inadequate pressurization during product curing and molding is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of curing and forming composite honeycomb sandwich structures, and in particular relates to a curing and forming tool and method for a large-size, high-precision, multi-fracture aluminum skin-aluminum honeycomb sandwich structure. Background Art

[0002] Honeycomb sandwich structures have special structural forms due to their specific use requirements. This requires the design of reasonable curing and molding tooling to ensure that the structural dimensional accuracy and surface accuracy of the honeycomb sandwich structure can meet the use requirements after curing and molding in the autoclave.

[0003] The general honeycomb sandwich structure forming tooling consists of three parts: positioning plate, positioning pins, and equalizing plate. The positioning plate and positioning pins are used to control the surface accuracy and dimensional accuracy of the honeycomb sandwich structure, and the equalizing plate is used to control the forming quality of the honeycomb sandwich structure. At present, the honeycomb sandwich structure has various forms. When forming a multi-fracture arc-shaped aluminum skin-aluminum honeycomb sandwich structure, it is necessary to consider the influence of the extension of the skin and honeycomb on the dimensional accuracy and forming quality, especially at the inflection point where the plane and the arc meet, quality defects are very likely to occur.

[0004] In order to avoid this manufacturing defect, it is necessary to design reasonable molding tooling and molding methods to improve the surface accuracy and molding quality of multi-fracture arc aluminum skin-aluminum honeycomb sandwich structure products. Summary of the invention

[0005] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art, to propose a multi-broken arc-shaped honeycomb sandwich structure curing molding tool and method, to achieve the use requirements of the multi-broken honeycomb sandwich structure tool with high surface precision, reliable molding method and reusable use.

[0006] The technical solution of the present invention is: a multi-broken arc honeycomb sandwich structure curing molding tool, the multi-broken arc honeycomb sandwich structure served includes an arc panel and M straight panels; the M straight panels are connected in series in sequence, one side of the straight panels after series connection is connected to the arc panel, and there are independent preset angles between two adjacent straight panels and between the straight panels and the arc panels, and the straight panels and the arc panels both include a lower skin, a honeycomb core, and an upper skin; it is characterized in that it includes a molding mold body, M+1 equalizing plates, M first splicing strips, M second splicing strips, and N side blocks; wherein the equalizing plates include M straight equalizing plates and 1 arc-surface equalizing plate, M>1, N>1;

[0007] The bottom surface of the molding mold body is a plane structure, and the upper surface is an arch. One side of the highest inflection point of the arch is a curved surface, and the other side is M planes spliced ​​at independent preset angles. The curved surface of the molding mold body is the same shape as the lower surface of the curved panel of the honeycomb sandwich structure, and the M planes of the molding mold body are the same shape as the lower surface of the straight plate of the honeycomb sandwich structure, which are used to lay the lower skin; the first splicing strip is installed at the splicing position of the curved panel and the lower skin of the straight plate, as well as at the splicing position of the lower skin of the adjacent straight plate, to fasten the lower skin at the splicing position; after the first splicing strip is assembled, the honeycomb core is pasted; the second splicing strip is installed at the splicing position of the curved panel and the upper skin of the straight plate, as well as at the splicing position of the adjacent straight plate At the splicing position of the upper skin on the plate; the first splicing strip and the second splicing strip at the splicing position of the arc panel and the straight plate extend along the normal direction of the arc panel; one side of the upper skin on which the second splicing strip is installed is attached to the honeycomb core, and a pressure equalizing plate is placed on the other side of the upper skin; N side blocks are connected to the upper surface of the forming mold body to fix the side edges of the connected straight plate and the side edges of the arc panel, and the height of the N side blocks after splicing is greater than the side thickness of the multi-broken arc honeycomb sandwich structure to be formed; M straight pressure equalizing plates and 1 arc-surface pressure equalizing plate are respectively placed on the skin of the straight plate and the upper skin of the arc panel, and follow the shape of the multi-broken arc honeycomb sandwich structure to provide a contact surface for the vacuum bag wrapped outside the honeycomb sandwich structure.

[0008] Furthermore, when built-in embedded parts are installed in the straight plates and curved panels of the multi-broken arc-shaped honeycomb sandwich structure, the built-in embedded parts are provided with pin holes, and the lower skin and the upper skin are both provided with avoidance holes corresponding to the positions of the pin holes; the curing molding tooling also includes positioning pins, and the molding mold body is provided with positioning interfaces according to the positions of the pin holes of the built-in embedded parts; the positioning pins pass through the pin holes of the built-in embedded parts and are fixed to the positioning interfaces of the molding mold body to realize the positioning of the skin on the molding mold body.

[0009] Furthermore, the positioning pin body is divided into a positioning pin end and a pin head, and the diameter of the positioning pin end is 0.03-0 mm smaller than the diameter of the pin hole of the embedded component, ensuring that the positioning pin end can be inserted into the pin hole of the embedded component.

[0010] Furthermore, when the multi-broken arc-shaped honeycomb sandwich structure has an edge sealing beam, the curing and molding tooling also includes a positioning block; the positioning block has a waist-shaped hole, the waist-shaped hole cooperates with the positioning pin end of the positioning pin, and the positioning block is fixed to the forming mold body by the positioning pin to realize the positioning of the edge sealing beam on the forming mold body.

[0011] Furthermore, the M straight pressure equalizing plates and the one curved pressure equalizing plate are provided with circular avoidance openings for the positioning nail heads, and the opening diameter is the diameter of the positioning nail head plus 1.5mm to 2mm; a splicing gap of 0.2mm to 0.4mm is reserved between two adjacent pressure equalizing plates.

[0012] Furthermore, the first splicing strip and the second splicing strip are made of the same material as the skin and are processed by sheet metal processing, and the first splicing strip and the second splicing strip are provided with splicing strip avoidance gaps at positions where the embedded parts pass.

[0013] Furthermore, based on the curing and molding tool of the present invention, a curing and molding method for a multi-broken arc-shaped honeycomb sandwich structure is provided, comprising the steps of:

[0014] S1. Design and manufacture curing and molding tooling according to the external dimensions of the multi-broken arc-shaped honeycomb sandwich structure to be formed;

[0015] S2. Lay the lower skin on the main body of the forming mold, note that the avoidance hole position on the lower skin corresponds to the positioning interface position of the main body of the forming mold, and place the first splicing strip at the splicing position of two adjacent lower skins;

[0016] S3. Place the embedded parts according to the positioning interface position of the molding die body, place the honeycomb core on the lower skin surface, splice the honeycomb core at the breaking inflection point, the splicing range of the honeycomb core is consistent with the size of the first splicing strip, control the profile accuracy of the whole board by adjusting the height of the honeycomb core at the inflection point, and fill the honeycomb core at the inflection point with adhesive for reinforcement;

[0017] S4, the edge sealing beam is fixed on the main body of the forming mold through positioning blocks and positioning pins;

[0018] S5. Place the second splicing plate and the upper skin on the honeycomb core, drive the positioning pins into the pin holes of the built-in embedded parts and fix them to the positioning interface of the molding die body, so as to realize the positioning of the honeycomb sandwich structure in the molding die body;

[0019] S6. Side blocks are installed on both sides of the forming mold body. The side blocks are connected to the forming mold body through positioning pins to form the outer contour of the multi-broken arc-shaped honeycomb sandwich structure. M straight equalizing plates and 1 arc-shaped equalizing plate are placed on the upper surface of the upper skin according to the profile of the honeycomb sandwich structure.

[0020] S7, wrapping the honeycomb sandwich structure obtained in step S6 with a vacuum bag, evacuating the vacuum bag, and placing the whole structure in an autoclave for curing and forming;

[0021] S8. Remove the curing and molding tooling to obtain a multi-fracture arc-shaped honeycomb sandwich structure.

[0022] Furthermore, when process areas are provided at the center positions of both ends of the lower skin and the upper skin, and holes are opened in the centers of the process areas; when laying the lower skin in step S2, it is also necessary: ​​positioning pins are used to fix the lower skin to the molding mold body through the holes in the process area of ​​the lower skin; when placing the upper skin in step S5, it is also necessary: ​​the holes in the process area of ​​the upper skin are inserted into the positioning pins for fixing the lower skin.

[0023] Furthermore, the honeycomb core height adjustment method in step S3 is: the height of the honeycomb core at the inflection point plus the height of the first splicing strip, the second splicing strip and the adhesive is the same as the height of the surrounding honeycomb core.

[0024] Furthermore, when removing the curing molding tooling as described in step S8, take out the positioning pins, remove the side block first, then remove the positioning block, and then remove the M straight pressure equalizing plates and 1 curved pressure equalizing plate from the straight plate and the curved plate respectively, and finally remove the honeycomb sandwich structure from the molding mold body.

[0025] The beneficial effects of the present invention compared with the prior art are:

[0026] (1) Positioning is performed by using positioning pins and threaded bottom holes of built-in metal connectors, which overcomes the problem that built-in metal connectors cannot be accurately positioned when the curved surface skin is extended, and improves the overall hole position accuracy of the multi-fracture curved honeycomb sandwich structure.

[0027] (2) The pressure equalizing plate is made of aluminum plate with a thickness of 0.4 to 0.6 mm, which has a simple structure and low manufacturing cost. At the same time, it has good conformability with the multi-broken arc honeycomb sandwich structure, which is convenient for pressurization and reduces the risk of insufficient pressurization during product curing and molding.

[0028] (3) The skin adopts the form of honeycomb core and splicing strip at the inflection point, which can effectively avoid local molding stress, so that the overall structure can be fully fitted with the main body of the molding mold, and the inflection point transition is smooth, effectively ensuring the molding quality at the inflection point of the multi-broken arc honeycomb sandwich structure.

[0029] (4) Since the edge sealing beam is positioned by positioning blocks and positioning pins, the need to add process holes to the skin is avoided, and the dimensional accuracy of the multi-fracture arc honeycomb sandwich structure can be effectively controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the overall structure of a multi-broken arc-shaped honeycomb sandwich produced in an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the honeycomb core structure of an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the assembly of the curing and molding tooling according to an embodiment of the present invention;

[0033] Figure 4 It is a schematic cross-sectional diagram of the assembly of the curing and molding tooling according to an embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of the skin of an embodiment of the present invention;

[0035] Figure 6It is a partial schematic diagram of the splicing position of the splicing strip according to an embodiment of the present invention;

[0036] Figure 7 It is a partial cross-sectional view of the functional interface of an embodiment of the present invention;

[0037] Figure 8 A partial cross-sectional view of a positioning block according to an embodiment of the present invention; DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with the accompanying drawings.

[0039] like Figure 1 As shown, the product 1 provided by the embodiment of the present invention includes two straight plates, one curved plate 2, an edge sealing beam and a functional interface 3, wherein a multi-fracture arc-shaped honeycomb sandwich structure is formed on the straight plate and the curved plate 2. The main functional interface 3 is an M5 and M10 threaded hole. After the honeycomb sandwich structure product is formed, the positioning pin 7 is pulled out, and the thread is processed on the inner wall of the pin hole of the embedded part to obtain the functional interface 3.

[0040] like Figure 2 As shown, the honeycomb sandwich structure is formed by curing the honeycomb core 4, adhesive 5 and skin 6.

[0041] like Figure 3 and Figure 4 As shown, the main structure of the curing molding tooling includes a molding mold body, M+1 equalizing plates 11, M first splicing strips, M second splicing strips, and N side blocks; wherein the equalizing plate 11 includes M straight equalizing plates and 1 curved equalizing plate, M>1, N>1.

[0042] The bottom surface of the molding mold body 8 is a plane structure, and the upper surface is an arch. One side of the inflection point of the highest point of the arch is a curved surface, and the other side is M planes spliced ​​at independent preset angles. The curved surface of the molding mold body 8 is the same shape as the lower surface of the curved panel of the honeycomb sandwich structure, and the M planes of the molding mold body 8 are the same shape as the lower surface of the straight plate of the honeycomb sandwich structure, which are used to lay the lower skin; the first splicing strip is installed at the splicing position of the curved panel and the lower skin of the straight plate, as well as at the splicing position of the lower skin of the adjacent straight plate, to fasten the lower skin at the splicing position; the honeycomb core is pasted after the first splicing strip is assembled; the second splicing strip is installed at the splicing position of the curved panel and the upper skin of the straight plate, as well as at the splicing position of the adjacent straight plate At the splicing position of the upper skin on the plate; the first splicing strip and the second splicing strip at the splicing position of the arc panel and the straight plate extend along the normal direction of the arc panel; one side of the upper skin on which the second splicing strip is installed is attached to the honeycomb core, and a pressure equalizing plate 11 is placed on the other side of the upper skin; N side blocks are connected to the upper surface of the forming mold body 8, and are used to fix the side edges of the connected straight plates and the side edges of the arc panel. The height of the N side blocks after splicing is greater than the side thickness of the multi-broken arc honeycomb sandwich structure to be formed; M straight pressure equalizing plates and 1 arc-surface pressure equalizing plate are respectively placed on the skin of the straight plate and the upper skin of the arc panel, and follow the shape of the multi-broken arc honeycomb sandwich structure to provide a contact surface for the vacuum bag wrapped outside the honeycomb sandwich structure.

[0043] In this embodiment, the positioning pins 7 include skin positioning pins, embedded positioning pins, side block pins and positioning block pins. The curing molding tool of the present invention is assembled into one with the multi-broken arc honeycomb sandwich structure to be formed through the embedded positioning pins and the side block pins, thereby simultaneously achieving the functions of maintaining the shape of the multi-broken arc honeycomb sandwich structure to be formed and positioning the functional interface.

[0044] In this embodiment, the molding surface of the molding mold body 8 includes an arc surface and two planes, presenting an arch structure. One arc surface is on one side of the inflection point of the arch, and the other side of the inflection point of the arch are two planes with a splicing angle. The molding mold body 8 is located at the bottom as a reference for the curing molding tooling and is supported on a plane; the lower surface of each lower skin is fitted with the molding mold body 8, and each lower skin is installed with a first splicing strip at the splicing position, and the honeycomb core is attached to the upper surface of the lower skin after the first splicing strip is installed; built-in embedded parts are placed in the honeycomb core according to the positioning interface position on the molding mold body 8, and the built-in embedded parts are provided with pin holes. The positioning pins 7 are inserted into the pin holes of the built-in embedded parts for positioning, and the edge sealing beams are fixed to the molding mold body 8 by the positioning blocks 9 and the positioning pins 7. Two ends; a second splicing strip is installed at the splicing position on the upper surface of the honeycomb core, and an upper skin is placed on the honeycomb core after the second splicing strip is installed; the side block is connected to the edge of the molding die body 8, and the inner cavity structure size composed of the side block and the positioning block 9 is consistent with the outer contour of the multi-broken arc honeycomb sandwich structure to be formed; the equalizing plate 11 is placed on the upper surface of the upper skin. In this embodiment, the equalizing plate 11 is composed of 3 independent split parts installed on the multi-broken arc honeycomb sandwich structure to be formed, and its shape is consistent with the honeycomb sandwich structure.

[0045] like Figure 4 , Figure 5 As shown, the lower skin and the upper skin in the present invention are in a splicing form, and a hole 13 is reserved on the skin to avoid the positioning pin 7 passing through. The hole 13 is also the design position of the functional interface after the product is formed. A process area 14 is set at the center of both ends of each skin. The size of the process area is a 20mm×20mm square area, and a Φ10mm process pin hole is opened in the middle to cooperate with the skin positioning pin 7 to achieve the positioning of the skin on the main body 8 of the forming mold. In this embodiment, the skin positioning pin uses a Φ10mm optical pin, and the multi-broken arc honeycomb sandwich structure panel to be formed is connected to the main hole 8 of the forming mold through the Φ10mm optical pin and the Φ10mm pin hole in the skin process area to fix the skin.

[0046] The honeycomb core is spliced ​​with the lower skin and the upper skin at two inflection points 10. Considering the centripetal expansion of the honeycomb core on the arc surface, the size of the second splicing strip is designed to be 0.5mm larger than the size of the first splicing strip to ensure the height matching of the lower skin and the upper skin at the joint. In the present invention, the size determination method of the first splicing strip and the second splicing strip at the splicing of the arc panel and the flat panel is to be calculated along the normal direction of the arc surface of the arc panel. In this embodiment, the thickness of the splicing strip is calculated as 20.5mm, and the sizes of the upper and lower splicing panels are 40mm and 40.5mm respectively.

[0047] like Figure 6 , Figure 8As shown, the upper skin and the lower skin are disconnected at two inflection points and a 0.2mm gap 15 is left; the height of the honeycomb core is trimmed at the overlapping area 17 of the skin and the splicing strip to obtain a high-profile honeycomb core 16, ensuring that the product surface is uniform and flat and the inflection point transition is smooth. The edge sealing beam is fixed to the molding die body 8 by edge positioning blocks 9 and positioning block nails, thereby improving the connection strength and structural rigidity of the curing molding tooling, and at the same time assembling the curing molding tooling as one.

[0048] like Figure 8 As shown, the positioning block 9 and the positioning block nail of the present invention are used to complete the positioning of the edge sealing beam. In this embodiment, the positioning block nail adopts an M5 link screw with a pin end. A waist-shaped groove is opened in the middle of the positioning block 9. The width of the waist-shaped groove is 8mm. The pin end size of the positioning block nail is 8mm, and the thread segment size is M5. The M5 positioning block nail is passed through the Φ5.2mm through hole of the positioning block 9 and fixed on the molding mold body 8. The edge sealing beam passes through the waist-shaped groove of the positioning block 9 to realize the positioning of the edge sealing beam on the molding mold body 8, thereby establishing the connection between the edge sealing beam and the molding mold body 8, and ensuring the consistency of the positioning reference of the edge sealing beam and the built-in embedded parts.

[0049] like Figure 3 As shown, the side blocks of the embodiment of the present invention are formed by aluminum plate processing, the side block thickness is 35mm, and the size is divided into three sizes of 280mm, 835mm, and 512mm, and the number is 4, 6, and 2 respectively. The 12 side blocks are fixed by using side block nails, and the 12 side blocks and the positioning block 9 together form an outer contour of 2325mm×940mm, so that the side blocks can completely cover the thickness of the side of the multi-broken arc honeycomb sandwich structure to be formed, realize the effective protection of the edge area of ​​the multi-broken arc honeycomb sandwich structure to be formed, and can accurately control the height size of the multi-broken arc honeycomb sandwich structure to be formed.

[0050] like Figure 7 As shown, the functional interface 3 of the multi-broken arc honeycomb sandwich structure to be formed in the present invention is positioned by using an embedded positioning pin; the embedded positioning pin body is divided into a positioning pin end and a pin head, and the positioning pin end of the embedded positioning pin is nailed into the pin hole of the built-in embedded part and connected with the main body 8 of the forming mold to complete the positioning, and the embedded positioning pin is pulled out of the formed honeycomb sandwich structure product, and the threaded M5 and M10 bottom holes of the functional interface 3 are processed on the inner wall of the pin hole of the built-in embedded part. In this embodiment, the diameter of the positioning pin end is 4.2mm and 8.5mm, and the tolerance is set to the bottom hole diameter (-0.03,0)mm. Due to the pin end matching, the pin hole accuracy of the built-in embedded part is completely guaranteed by the mold with higher processing accuracy, which can well control the accuracy of the final functional interface 3 of the multi-broken arc honeycomb sandwich structure to be formed; the first splicing strip and the second splicing strip are provided with a splicing strip avoidance gap 18 at the position where the embedded positioning pin passes.

[0051] When the honeycomb core is spliced, the size of the splicing area is consistent with the size of the first splicing strip, and the honeycomb core and the honeycomb core are embedded with adhesive at the splicing. For the large-angle turning points of the straight plate and the curved plate, the honeycomb core grid is cross-cut and filled with adhesive to improve the overall fit. In this embodiment, when the honeycomb core is filled, the honeycomb core grid is filled with foam glue in a 1 / 2 filling method. At the splicing position of the curved plate and the straight plate, and the splicing position of the straight plate and the straight plate, the honeycomb core height is matched to control the surface accuracy of the whole plate. The principle of honeycomb core height matching is: the height of the honeycomb core at the turning point plus the height of the first splicing strip, the second splicing strip and the surrounding honeycomb core are the same.

[0052] The positioning pins 7 in the embodiment of the present invention are made of 45# steel. After rough machining with allowance, the positioning pins 7 are first subjected to tempering treatment to improve their strength, and then subjected to surface blackening treatment to improve their corrosion resistance after fine machining to the final size.

[0053] Using the curing and forming tooling of the present invention, a curing and forming method for a multi-broken arc-shaped honeycomb sandwich structure comprises the following steps:

[0054] S1. Design and manufacture curing and molding tooling according to the external dimensions of the multi-broken arc-shaped honeycomb sandwich structure to be formed;

[0055] S2. Lay the lower skin on the molding die body 8. Note that the avoidance hole position on the lower skin corresponds to the positioning interface position of the molding die body 8. Place the first splicing strip at the splicing position of two adjacent lower skins.

[0056] S3, placing the embedded parts with reference to the positioning interface position of the molding mold body 8, placing the honeycomb core on the lower skin surface, splicing the honeycomb core at the breaking inflection point, the splicing range of the honeycomb core is consistent with the size of the first splicing strip, the honeycomb core at the inflection point is height-controlled to control the profile accuracy of the entire board, and the honeycomb core at the inflection point is reinforced by filling the adhesive;

[0057] S4, the edge sealing beam is fixed on the molding die body 8 through the positioning block 9 and the positioning pin 7;

[0058] S5, placing the second splicing plate and the upper skin on the honeycomb core, driving the positioning pins 7 into the pin holes of the built-in embedded parts and fixing them to the positioning interface of the molding die body 8, so as to realize the positioning of the honeycomb sandwich structure in the molding die body 8;

[0059] S6. Side blocks are installed on both sides of the molding die body 8. The side blocks are connected to the molding die body 8 through positioning pins 7 to form the outer contour of a multi-broken arc-shaped honeycomb sandwich structure. M straight pressure equalizing plates and one arc-shaped pressure equalizing plate are placed on the upper surface of the upper skin according to the profile of the honeycomb sandwich structure.

[0060] S7, wrapping the honeycomb sandwich structure obtained in step S6 with a vacuum bag, evacuating the vacuum bag, and placing the whole structure in an autoclave for curing and forming;

[0061] S8. Remove the curing and molding tooling to obtain a multi-fracture arc-shaped honeycomb sandwich structure.

[0062] Furthermore, when process areas are provided at the center positions of both ends of the lower skin and the upper skin, and holes are opened in the centers of the process areas; when laying the lower skin in step S2, it is also necessary that: positioning pins 7 fix the lower skin to the molding mold body 8 through the holes in the process area of ​​the lower skin; when placing the upper skin in step S5, it is also necessary that: the holes in the process area of ​​the upper skin are inserted into the positioning pins 7 for fixing the lower skin.

[0063] Furthermore, the honeycomb core height adjustment method in step S3 is: the height of the honeycomb core at the inflection point plus the height of the first splicing strip, the second splicing strip and the adhesive is the same as the height of the surrounding honeycomb core.

[0064] Furthermore, when removing the curing molding tooling as described in step S8, take out the positioning pin 7, first remove the side block, then remove the positioning block 9, and then remove M straight pressure equalizing plates and 1 curved pressure equalizing plate from the straight plate and the curved plate respectively, and finally remove the honeycomb sandwich structure from the molding mold body 8.

[0065] Audio nondestructive testing was performed on the multi-broken arc aluminum skin-aluminum honeycomb sandwich structure made by the curing molding tooling of the present invention. The results showed that no bonding defects exceeding the requirements of GJB1719-1993 for Class I parts were found between the lower skin, the upper skin, the honeycomb core and the functional interface 3, and the product bonding quality met the use requirements.

[0066] The size and shape accuracy of the manufactured multi-broken arc aluminum skin-aluminum honeycomb sandwich structure were tested. The results showed that the maximum deviation of the product's outer dimensions was 0.4mm (the index was ≤1mm), the maximum flatness was 0.5mm (the index was ≤1.0mm), The local flatness of the equipment installation surface formed by the functional interface 3 is up to 0.15 mm (the indicator is ≤0.2 mm), and the angle of the product 1 is 162.03° (the indicator is 162°±0.1°).

[0067] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A multi-broken arc honeycomb sandwich structure curing molding tool, the multi-broken arc honeycomb sandwich structure comprises an arc panel and M straight panels, the M straight panels are sequentially connected in series, one side of the straight panels after being connected in series is connected to the arc panel, there are independent preset angles between two adjacent straight panels and between the straight panels and the arc panel, the straight panels and the arc panel both comprise a lower skin, a honeycomb core, and an upper skin; characterized in that: It comprises a forming mold body (8), M+1 equalizing plates (11), M first splicing strips, M second splicing strips, and N side blocks; wherein the equalizing plates (11) comprise M straight equalizing plates and 1 curved equalizing plate, M>1, and N>1; The bottom surface of the molding die main body (8) is a plane structure, and the upper surface is an arch. One side of the highest inflection point of the arch is a curved surface, and the other side is M planes spliced ​​at independent preset angles. The curved surface of the molding die main body (8) has the same shape as the lower surface of the curved panel of the honeycomb sandwich structure, and the M planes of the molding die main body (8) have the same shape as the lower surface of the flat plate of the honeycomb sandwich structure, and are used to lay down the lower skin. The first splicing strip is installed at the splicing position of the curved panel and the lower skin of the flat plate, and at the splicing position of the lower skin of the adjacent flat plate, and is used to fasten the lower skin at the splicing position. After the first splicing strip is assembled, the honeycomb core is glued; The second splicing strip is installed at the splicing position of the skin of the curved panel and the straight panel, and at the splicing position of the skin of the adjacent straight panel; the first splicing strip and the second splicing strip at the splicing position of the curved panel and the straight panel extend along the normal direction of the curved panel; one side of the upper skin on which the second splicing strip is installed is attached to the honeycomb core, and a pressure equalizing plate (11) is placed on the other side of the upper skin; N edge blocks are connected to the upper surface of the forming mold body (8) to fix the side edges of the connected straight panels and the side edges of the curved panel, and the height of the N edge blocks after splicing is greater than the side thickness of the multi-broken arc-shaped honeycomb sandwich structure to be formed; M straight pressure equalizing plates and 1 curved surface pressure equalizing plate are respectively placed on the upper skin of the straight panel and the upper skin of the curved panel, and follow the shape of the multi-broken arc-shaped honeycomb sandwich structure to provide a contact surface for the vacuum bag wrapped outside the honeycomb sandwich structure.

2. The multi-broken arc-shaped honeycomb sandwich structure curing molding tool according to claim 1, characterized in that: Built-in embedded parts are installed in the straight plates and curved panels of the multi-broken arc-shaped honeycomb sandwich structure, and the built-in embedded parts are provided with pin holes. The lower skin and the upper skin are both provided with avoidance holes corresponding to the positions of the pin holes. The curing molding tool also includes a positioning pin (7), and a positioning interface is set on the molding mold body (8) according to the position of the pin hole of the built-in embedded part. The positioning pin (7) passes through the pin hole of the built-in embedded part and is fixed to the positioning interface of the molding mold body (8), so as to realize the positioning of the skin on the molding mold body (8).

3. The multi-broken arc-shaped honeycomb sandwich structure curing molding tool according to claim 2, characterized in that: The main body of the positioning pin (7) is divided into a positioning pin end and a pin head. The diameter of the positioning pin end is 0.03-0 mm smaller than the diameter of the pin hole of the embedded component, ensuring that the positioning pin end can be inserted into the pin hole of the embedded component.

4. The multi-broken arc-shaped honeycomb sandwich structure curing molding tool according to claim 3, characterized in that: When the multi-broken arc-shaped honeycomb sandwich structure has an edge sealing beam, the curing and forming tooling also includes a positioning block (9); the positioning block (9) has a waist-shaped hole, the waist-shaped hole matches the positioning pin end of the positioning pin (7), and the positioning block (9) is fixed to the forming mold body (8) through the positioning pin (7), so as to realize the positioning of the edge sealing beam on the forming mold body (8).

5. The multi-broken arc-shaped honeycomb sandwich structure curing molding tool according to claim 1, characterized in that: The M straight pressure equalizing plates and the one curved pressure equalizing plate are provided with circular avoidance openings for the heads of the positioning pins (7), the diameter of the openings being the diameter of the heads of the positioning pins (7) plus 1.5 mm to 2 mm; a splicing gap of 0.2 mm to 0.4 mm is reserved between two adjacent pressure equalizing plates (11).

6. The multi-broken arc-shaped honeycomb sandwich structure curing and forming tooling according to claim 1, characterized in that: The first splicing strip and the second splicing strip are made of the same material as the skin and are processed by sheet metal. The first splicing strip and the second splicing strip are provided with splicing strip avoidance gaps at positions where the embedded parts pass.

7. A curing and forming method for a multi-broken arc-shaped honeycomb sandwich structure based on the tooling of claim 4, characterized in that: Includes steps: S1. Design and manufacture curing and molding tooling according to the external dimensions of the multi-broken arc-shaped honeycomb sandwich structure to be formed; S2. Lay the lower skin on the molding die main body (8), note that the avoidance hole position on the lower skin corresponds to the positioning interface position of the molding die main body (8), and place a first splicing strip at the splicing position of two adjacent lower skins; S3, placing the embedded parts with reference to the positioning interface position of the molding die body (8), placing the honeycomb core on the lower skin surface, splicing the honeycomb core at the breaking inflection point, the splicing range of the honeycomb core is consistent with the size of the first splicing strip, the honeycomb core at the inflection point is height-adjusted to control the entire panel profile accuracy, and the honeycomb core at the inflection point is reinforced by filling the adhesive; S4, the edge sealing beam is fixed on the molding die body (8) through the positioning block (9) and the positioning pin (7); S5, placing a second splicing plate and an upper skin on the honeycomb core, driving a positioning pin (7) into a pin hole of a built-in embedded part and fixing it to a positioning interface of a molding die body (8), thereby achieving positioning of the honeycomb sandwich structure on the molding die body (8); S6, side blocks are installed on both sides of the molding die main body (8), and the side blocks are connected to the molding die main body (8) through positioning pins (7), forming the outer contour of a multi-broken arc-shaped honeycomb sandwich structure, and M straight equalizing plates and one arc-shaped equalizing plate are placed on the upper surface of the upper skin according to the profile of the honeycomb sandwich structure; S7, wrapping the honeycomb sandwich structure obtained in step S6 with a vacuum bag, evacuating the vacuum bag, and placing the whole structure in an autoclave for curing and forming; S8. Remove the curing and molding tooling to obtain a multi-fracture arc-shaped honeycomb sandwich structure.

8. The curing molding method of a multi-broken arc-shaped honeycomb sandwich structure according to claim 7, characterized in that: Process areas are provided at the center of both ends of the lower skin and the upper skin, and a hole is opened in the center of the process area; when laying the lower skin in step S2, it is also necessary: ​​positioning pins (7) are used to fix the lower skin on the molding mold body (8) through the holes in the lower skin process area; when placing the upper skin in step S5, it is also necessary: ​​the holes in the upper skin process area are inserted into the positioning pins (7) for fixing the lower skin.

9. The curing molding method of a multi-broken arc-shaped honeycomb sandwich structure according to claim 7, characterized in that: The honeycomb core height adjustment method in step S3 is: the height of the honeycomb core at the inflection point plus the height of the first splicing strip, the second splicing strip and the adhesive is the same as the height of the surrounding honeycomb core.

10. The curing molding method of a multi-broken arc-shaped honeycomb sandwich structure according to claim 7, characterized in that: When removing the curing molding tooling in step S8, take out the positioning pin (7), first remove the side block, then remove the positioning block (9), and then remove M straight pressure equalizing plates and 1 curved pressure equalizing plate from the straight plate and the curved plate respectively, and finally remove the honeycomb sandwich structure from the molding mold body (8).

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