Forming die and method for high-aspect-ratio composite multi-cavity box section structural beam

Abstract

The invention discloses a forming die and method for a high-aspect-ratio composite multi-cavity box section structural beam. The bottom and the two side walls of the mold core assembly (1) are connected with the bottom supporting frame (2), the side supporting frame A (3) and the side supporting frame B (4) respectively. The mold core assembly (1) comprises a base plate (5), a cavity core mold assembly (6) is arranged on the upper surface of the base plate (5), a beam core mold assembly (7) is arranged on the upper surface of the cavity core mold assembly (6), a side mold assembly A (8) and a side mold assembly B (9) which can be oppositely combined in the transverse direction are arranged on the two sides of the cavity core mold assembly (6) respectively, and the cavity core mold assembly (6) can be surrounded after the side mold assembly A and the side mold assembly B are oppositely combined. A clamping groove (10) formed at the top after folding can limit the beam core mold assembly (7); and after the side mold assemblies A and B are oppositely combined, the top is covered with a top cover (11). According to the invention, the product forming quality can be ensured, and the manufacturing cost of similar products can be greatly reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of composite material parts manufacturing, and in particular relates to a large aspect ratio composite material multi-cavity box-segment structural beam forming die and method. Background Art

[0002] Large aspect ratio composite multi-cavity box-segment structural beams are currently widely used in fixed-wing aircraft horizontal tail structures, wing structures, etc. In response to research and development needs, a new large aspect ratio composite multi-cavity box-segment structural beam is required. The beam span is 8400mm, which is twice the length of the existing parts of the same model. It is a 12-single closed cavity structure, an integrated structure formed by 12 dimensional support ribs-integral beams-double-side skins. The structure is shown in Figure 8 , Fig. 9 .

[0003] The vacuum bag-autoclave molding process and liquid molding process are the two mainstream molding methods currently used. However, both methods have the problem of extrusion damage to parts due to thermal expansion of the mold. The currently widely used solution is to use Invar steel with a smaller thermal expansion effect to manufacture the mold. However, the material cost and processing fee of Invar steel are more than 10 times that of ordinary steel materials. Using Invar steel as the main material for part molds has greatly increased the manufacturing cost of the parts. Summary of the invention

[0004] The purpose of the present invention is to provide a large aspect ratio composite material multi-cavity box-segment structural beam forming die and method. The present invention can ensure the product forming quality and greatly reduce the manufacturing cost of similar products.

[0005] The technical solution of the present invention is: a large aspect ratio composite material multi-cavity box-segment structural beam forming mold, comprising: a core mold assembly, the bottom and two side walls of the core mold assembly are respectively connected to a bottom support frame, a side support frame A and a side support frame B; the core mold assembly comprises a base plate, the upper surface of the base plate is provided with a cavity core mold assembly, the upper surface of the cavity core mold assembly is provided with a beam core mold assembly, the two sides of the cavity core mold assembly are respectively provided with a side mold assembly A and a side mold assembly B that can be laterally matched, after the side mold assemblies A and B are matched, they can surround the cavity core mold assembly, and the groove formed on the top after the matching can limit the beam core mold assembly; after the side mold assemblies A and B are matched, the top is covered with a top cover.

[0006] In the aforementioned large aspect ratio composite material multi-cavity box-segment structural beam forming mold, the cavity core mold assembly includes one or more core units arranged along the length direction of the substrate, and the core unit includes a center block, and the two sides of the center block are connected with side inserts A and side inserts B through mortise and tenon structures. The mortise and tenon structure can ensure that the center block is pulled out from between the two inserts along the bottom.

[0007] In the aforementioned large aspect ratio composite material multi-cavity box-segment structural beam forming die, the side wall where the central block contacts the side insert block is designed with a draft angle.

[0008] In the aforementioned large aspect ratio composite material multi-cavity box-segment structural beam forming mold, the core units at both ends and the middle position of the base plate are elastic cores.

[0009] In the aforementioned large aspect ratio composite material multi-cavity box-segment structural beam forming mold, the beam core mold assembly includes one or more beam core units arranged along the length direction of the substrate, and the beam core unit includes a pair of beam core inserts A and beam core inserts B that are laterally matched, and the matching surfaces of the beam core inserts A and B are arranged in an inclined manner.

[0010] In the aforementioned large aspect ratio composite material multi-cavity box-segment structural beam forming mold, the top surfaces of the beam core inserts A and B are respectively provided with locking modules A and locking modules B, which, after being matched, cooperate with the locking grooves arranged on the bottom surface of the top cover.

[0011] In the aforementioned large aspect ratio composite material multi-cavity box-segment structural beam forming mold, the side mold components A and B are both frame beam structures.

[0012] The molding method of the aforementioned large aspect ratio composite material multi-cavity box-segment structural beam molding die comprises the following steps:

[0013] S1. The center block, the side panel A and the side panel B are connected by a mortise and tenon structure to form a core unit, and then the ribs of the multi-cavity box segment structural beam are laid on the end surface of the core unit;

[0014] S2. The core units are sequentially installed on the substrate to form a cavity core mold assembly; the lower frame main beam of the multi-cavity box segment structural beam is laid on the top surface of the cavity core mold assembly;

[0015] S3. Precompact the laid ribs and lower frame main beams by vacuum precompacting;

[0016] S4. The beam core inserts A and B are combined to form a beam core unit, the beam core units are spliced ​​to form a beam core mold assembly, and the upper frame main beam of the multi-cavity box segment structural beam is laid on the beam core mold assembly;

[0017] S5. Position the laid upper frame main beam together with the beam core mold assembly to the top surface of the upper frame main beam;

[0018] S6. Lay the skin A and skin B of the multi-cavity box-segment structural beam on the inner surfaces of the side mold assemblies A and B respectively; after the laying is completed, the side mold assemblies A and B are aligned so that the groove clamps the beam core mold assembly from the side and fixes it on the substrate;

[0019] S7. Buckle the top cover on the top surface of the side mold components A and B after they are aligned, and make the locking groove cooperate with the locked modules A and B after they are aligned to complete the assembly of the core assembly; after completion, install the bottom support frame, the side support frame A and the side support frame B around the core assembly;

[0020] S8. Inject resin into the core assembly for liquid molding.

[0021] The advantages of the present invention are:

[0022] 1. The present invention effectively solves the deformation effect caused by thermal expansion effect by adopting a split core mold assembly and a replaceable soft-hard combination mold. The mold of the present invention can ensure the molding quality of the product by combining with the liquid molding process and can greatly reduce the manufacturing cost of similar products.

[0023] 2. The present invention adopts controllable thermal expansion mold design technology, and replaces the steel mold cores on both sides and in the middle with a forming mold with a foam core material (elastic core), thereby downgrading the thermal expansion effect of the 8-meter product and solving the problem of product damage caused by thermal expansion of the mold. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the present invention;

[0025] Figure 2 It is a schematic diagram of the structure of the mold core assembly;

[0026] Figure 3 It is a schematic diagram of the connection between the cavity core mold assembly and the beam core mold assembly;

[0027] Figure 4 It is a schematic diagram of the structure of side mold components A and B;

[0028] Figure 5 It is a schematic diagram of the structure of the cavity core mold assembly and the beam core mold assembly;

[0029] Figure 6 It is the front view of the cavity core mold assembly and the beam core mold assembly;

[0030] Figure 7 It is a schematic diagram of the side mold component A and the side mold component B being matched;

[0031] Figure 8 It is a schematic diagram of the structure of a multi-cavity box-segment structural beam;

[0032] Fig. 9 for Figure 8 AA section view. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0034] The features and illustrative embodiments of various aspects of the present invention will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention. The present invention is by no means limited to any specific settings and methods proposed below, but covers any improvements, replacements and modifications of structures, methods, devices without departing from the spirit of the present invention. In the accompanying drawings and the following description, known structures and technologies are not shown to avoid unnecessary ambiguity in the present invention.

[0035] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other, and the embodiments can refer to and quote each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0036] Example 1. A high aspect ratio composite multi-cavity box-segment structural beam forming die, comprising: Figure 1-Figure 9 , including a core mold assembly 1, the bottom and two side walls of the core mold assembly 1 are respectively connected to the bottom support frame 2, the side support frame A3 and the side support frame B4; the core mold assembly 1 includes a base plate 5, the upper surface of the base plate 5 is provided with a cavity core mold assembly 6, the upper surface of the cavity core mold assembly 6 is provided with a beam core mold assembly 7, the two sides of the cavity core mold assembly 6 are respectively provided with side mold assemblies A8 and side mold assemblies B9 which can be laterally matched, after the side mold assemblies A and B are matched, they can surround the cavity core mold assembly 6, and the card groove 10 formed on the top after the matching can limit the beam core mold assembly 7; after the side mold assemblies A and B are matched, the top is covered with a top cover 11.

[0037] The aforementioned cavity core mold assembly 6 includes one or more core units arranged along the length direction of the substrate 5, and the core units include a center block 61, and the two sides of the center block 61 are connected with side inserts A62 and side inserts B63 through mortise and tenon structures. The mortise and tenon structure can ensure that the center block 61 is pulled out from between the two inserts along the bottom.

[0038] The side walls of the aforementioned center block 61 that contact the side insert blocks are designed with a draft angle.

[0039] The core units at both ends and the middle of the base plate 5 are elastic cores (foam material). The inner metal modules in the middle section of the box section and on both sides are replaced with hard foam to establish a buffer structure and eliminate the influence of thermal expansion during the heating process of the mold.

[0040] The aforementioned beam core mold assembly 7 includes one or more beam core units arranged along the length direction of the base plate 5, and the beam core units include a pair of beam core inserts A71 and beam core inserts B72 that are laterally matched. The matching surfaces of the beam core inserts A and B are inclined to facilitate demoulding.

[0041] The top surfaces of the aforementioned beam core inserts A and B are respectively provided with a locking module A73 and a locking module B74 . After the locking modules A and B are matched, they cooperate with the locking grooves provided on the bottom surface of the top cover 11 .

[0042] The aforementioned side mold components A and B are both frame beam structures. The frame structure achieves the dual effects of reducing weight and strengthening mold rigidity.

[0043] The molding method of the aforementioned large aspect ratio composite material multi-cavity box-segment structural beam molding die comprises the following steps:

[0044] S1. The center block 61, the side panel A62 and the side panel B63 are connected by a mortise and tenon structure to form a core unit, and then the rib 121 of the multi-cavity box segment structural beam 12 is laid on the end surface of the core unit;

[0045] S2. The core units are sequentially installed on the substrate 5 to form a cavity core mold assembly 6; the lower frame main beam 122 of the multi-cavity box segment structural beam 12 is laid on the top surface of the cavity core mold assembly 6;

[0046] S3. The laid ribs 121 and the lower frame main beam 122 are vacuum pre-compacted; the pre-compacting process is: using sealing adhesive tape, vacuum bag and breathable felt to vacuum package the assembled substrate 5 and the cavity core mold assembly 6, and the vacuum degree is not less than 0.08Mpa; the packaged mold is placed in an oven to start pre-compacting, and the pre-compacting process parameters are: (60~100)℃×(30~60)min;

[0047] S4. The beam core inserts A and B are combined to form a beam core unit, and the beam core units are spliced ​​to form a beam core mold assembly 7, and the upper frame main beam 123 of the multi-cavity box segment structural beam 12 is laid on the beam core mold assembly 7;

[0048] S5. The completed upper frame main beam 123 together with the beam core mold assembly 7 is positioned and placed on the top surface of the upper frame main beam 123;

[0049] S6. The skin A124 and the skin B125 of the multi-cavity box-segment structural beam 12 are laid on the inner surfaces of the side mold assemblies A and B respectively; after the laying is completed, the side mold assemblies A and B are aligned so that the groove 10 clamps the beam core mold assembly 7 from the side and is fixed to the substrate 5;

[0050] S7. Buckle the top cover 11 on the top surface of the side mold assemblies A and B after they are aligned, and make the locking groove cooperate with the locked modules A and B after they are aligned to complete the assembly of the core assembly 1; after completion, install the bottom support frame 2, the side support frame A3 and the side support frame B4 around the core assembly 1;

[0051] S8. Inject resin into the core component 1 for liquid molding. Resin injection: Set the oven environment temperature to no higher than 90℃, turn on the blast and heating, and when the mold temperature is 75±5℃, the insulation time is not less than 1h, and the resin injection process is carried out. When the mold temperature is in the range of 60℃~80℃, place the resin in the injection barrel and vacuum degas. During degassing, the vacuum degree should be greater than 0.08Mpa, and the degassing time should be at least 30min. After the resin is degassed, remove the vacuum of the resin barrel. Under natural conditions, the resin is injected for about 5min~10min; connect the compressed air, keep the air pressure at 0.05Mpa, open the valve, and inject. After all the glue outlets are closed, close all valves, and hold the glue for no less than 5min; when the pressure rises to 0.1Mpa, open the valve, and inject. After all the glue outlets of the mold have glued out, close all valves, hold the glue for 5min, and reciprocate 1~3 times; when the pressure rises to 0.15Mpa, open the valve, and inject. After all the glue outlets of the mold have been glued, all valves are closed, and the glue is held for no less than 5 minutes, and the cycle is repeated 1 to 3 times; when the pressure rises to 0.2Mpa, the valve is opened and the injection is performed. After all the glue outlets have been glued, all valves are closed, and the glue is held for no less than 5 minutes, and the cycle is repeated 1 to 3 times; when the pressure rises to 0.25Mpa, the valve is opened and the injection is performed. After all the glue outlets have been glued, all valves are closed, and the glue is held for no less than 5 minutes, and the cycle is repeated 1 to 3 times; when the pressure rises to 0.3Mpa, the valve is opened and the injection is performed. After all the glue outlets have been glued, all valves are closed, and the glue is held for no less than 5 minutes, and the cycle is repeated 1 to 3 times; when the pressure rises to 0.35Mpa, the valve is opened and the injection is performed. After all the glue outlets have been glued, all valves are closed, and the glue is held for no less than 5 minutes, and the cycle is repeated 1 to 3 times. After the injection is completed, close all the glue outlets; move the glue injection tank out of the oven and clean it in time.

[0052] S9. After the resin injection is completed, the temperature starts to rise. When the mold temperature rises to (160±5), keep it warm for (1~1.5) hours. Continue to heat up. When the mold temperature rises to (185±5℃)℃, keep it warm for (3~6) hours. After the insulation is completed, start cooling down. When the mold temperature drops to ≤60℃, the curing is completed.

[0053] S10. When the mold temperature drops below 60°C, remove the mold from the oven, remove the bottom support frame 2, remove the top cover 11, and the substrate 5;

[0054] S11. Remove the beam core block assembly and the cavity core block assembly in the order of beam core block B72, beam core block A71, center block 61, side block A62 and side block B63;

[0055] S12. Disassemble the side support frame A3, the side support frame B4, the side mold assembly A8 and the side mold assembly B9;

[0056] S13. Remove the workpiece, mark the workpiece, and clean the mold.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the field can easily think of various equivalent modifications or substitutions within the technical scope disclosed by the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A high aspect ratio composite multi-cavity box-segment structural beam forming die, characterized in that: The invention comprises a mold core assembly (1), the bottom and two side walls of the mold core assembly (1) are respectively connected to a bottom support frame (2), a side support frame A (3) and a side support frame B (4); the mold core assembly (1) comprises a base plate (5), the upper surface of the base plate (5) is provided with a cavity core mold assembly (6), the upper surface of the cavity core mold assembly (6) is provided with a beam core mold assembly (7), and the two sides of the cavity core mold assembly (6) are respectively provided with a side mold assembly A (8) and a side mold assembly B (9) which can be matched in the transverse direction, and when the side mold assemblies A and B are matched, they can surround the cavity core mold assembly (6), and the clamping groove (10) formed on the top after the matching can limit the beam core mold assembly (7); when the side mold assemblies A and B are matched, the top is covered with a top cover (11).

2. The high aspect ratio composite multi-cavity box-segment structural beam forming mold according to claim 1, characterized in that: The cavity core mold assembly (6) includes one or more core units arranged along the length direction of the base plate (5), and the core units include a center block (61). The two sides of the center block (61) are connected with side inserts A (62) and side inserts B (63) through a mortise and tenon structure. The mortise and tenon structure can ensure that the center block (61) can be pulled out from between the two inserts along the bottom.

3. The high aspect ratio composite multi-cavity box-segment structural beam forming die according to claim 2, characterized in that: The side wall of the central block (61) in contact with the side insert block is designed with a draft angle.

4. The high aspect ratio composite multi-cavity box-segment structural beam forming die according to claim 2, characterized in that: The core units located at both ends and the middle of the base plate (5) are elastic cores.

5. The high aspect ratio composite multi-cavity box-segment structural beam forming die according to claim 1, characterized in that: The beam core mold assembly (7) comprises one or more beam core units arranged along the length direction of the base plate (5), wherein the beam core units comprise a pair of beam core inserts A (71) and beam core inserts B (72) which are aligned in the transverse direction, and the aligned surfaces of the beam core inserts A and B are arranged in an inclined manner.

6. The high aspect ratio composite multi-cavity box-segment structural beam forming die according to claim 5, characterized in that: The top surfaces of the beam core inserts A and B are respectively provided with a locking module A (73) and a locking module B (74). After the locking modules A and B are matched, they cooperate with the locking grooves provided on the bottom surface of the top cover (11).

7. The high aspect ratio composite multi-cavity box-segment structural beam forming die according to claim 1, characterized in that: The side formwork components A and B are both frame beam structures.

8. A method for forming a high aspect ratio composite material multi-cavity box-segment structural beam forming mold according to any one of claims 1 to 7, characterized in that: The steps include: S1. The center block (61), the side panel A (62) and the side panel B (63) are connected by a mortise and tenon structure to form a core unit, and then the rib (121) of the multi-cavity box segment structural beam (12) is laid on the end surface of the core unit; S2. The core units are sequentially installed on the substrate (5) to form a cavity core mold assembly (6); the lower frame main beam (122) of the multi-cavity box segment structural beam (12) is laid on the top surface of the cavity core mold assembly (6); S3. Precompact the laid ribs (121) and the lower frame beam (122) by vacuum precompacting; S4. The beam core inserts A and B are combined to form a beam core unit, and the beam core units are spliced ​​to form a beam core mold assembly (7), and the upper frame main beam (123) of the multi-cavity box segment structural beam (12) is laid on the beam core mold assembly (7); S5. Position the completed upper frame main beam (123) together with the beam core mold assembly (7) to the top surface of the upper frame main beam (123); S6. The skin A (124) and the skin B (125) of the multi-cavity box-segment structural beam (12) are laid on the inner surfaces of the side mold assemblies A and B respectively; after the laying is completed, the side mold assemblies A and B are aligned so that the groove (10) clamps the beam core mold assembly (7) from the side and is fixed on the base plate (5); S7. Buckle the top cover (11) on the top surface of the side mold assemblies A and B after they are aligned, and make the locking groove match the locked modules A and B after they are aligned, so as to complete the assembly of the core assembly (1); after completion, install the bottom support frame (2), the side support frame A (3) and the side support frame B (4) around the core assembly (1); S8. Inject resin into the core mold assembly (1) for liquid molding.

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