A forming die for a toroidal honeycomb sandwich composite structural member

Abstract

The present application relates to the technical field of composite material forming, in particular to a forming die for annular honeycomb sandwich composite structural member. The forming die comprises a main die body, the main die body comprises a frame, a baffle and at least three sub-die bodies which are sequentially and detachably connected to form a ring structure, the frame is arranged inside the ring structure and is used for supporting each sub-die body, and the baffle is arranged in the circumferential direction of the opposite ends of the ring structure; wherein at least one sub-die body is provided with a draft angle along the circumferential direction and the axial direction, and the circumferential outer wall of the ring structure is used for laying up the prepreg of the annular honeycomb sandwich composite structural member. The purpose of the forming die for the annular honeycomb sandwich composite structural member is to solve the problems of difficult laying up of the annular composite structural member, difficult demolding after forming and difficult numerical control machining.

Description

Technical Field

[0001] This invention relates to the field of composite material molding technology, and specifically to a molding die for a ring-shaped honeycomb sandwich composite material structure. Background Technology

[0002] Composite material molding dies are crucial equipment in the fabrication of composite structural components, and the level of their structural design methodology determines the manufacturing capability and product quality of composite materials. Based on structural design, composite material molding dies are classified into: male molds, female molds, combination molds, and core molds.

[0003] The finishing of composite materials generally involves placing the structural parts on a dedicated milling fixture after demolding, and then machining the composite parts according to the fixture reference and machining lines to remove excess material and obtain the net dimensions of the composite parts.

[0004] Aircraft and engines contain various closed annular composite honeycomb sandwich structures. To ensure the quality of the inner surface of the structural components and to facilitate the prepreg stacking operation and quality control, a positive mold structure is required. If the mold structure design is not reasonable, demolding the parts after molding is a problem in the manufacturing process.

[0005] After demolding, the ring-shaped composite material structural parts are difficult to place into the milling fixture, and there is an error in secondary positioning.

[0006] Therefore, the inventors have provided a molding die for a ring-shaped honeycomb sandwich composite material structure. Summary of the Invention

[0007] (1) Technical problems to be solved

[0008] This invention provides a molding die for a ring-shaped honeycomb sandwich composite material structure, which solves the technical problems of difficult stacking, difficult demolding after molding, and difficult CNC machining of ring-shaped composite material structures.

[0009] (2) Technical solution

[0010] This invention provides a molding die for a ring-shaped honeycomb sandwich composite material structure, comprising a main mold body, the main mold body including a frame, a retaining edge, and at least three parting mold bodies that are detachably connected end to end to form a ring structure. The frame is disposed inside the ring structure and is used to support each parting mold body. The retaining edge is disposed circumferentially at opposite ends of the ring structure. At least one parting mold body is provided with a draft angle along its circumferential and axial directions. The circumferential outer wall of the ring structure is used to lay the prepreg of the ring-shaped honeycomb sandwich composite material structure.

[0011] Furthermore, the annular structure includes a first parting body, a second parting body, a third parting body, and a fourth parting body. The first parting body and the second parting body are symmetrically distributed, and the first parting body and the second parting body are provided with the draft angle along their circumferential and axial directions.

[0012] Furthermore, the circumferential proportion of the first module is smaller than the circumferential proportion of the third module.

[0013] Furthermore, the circumferential proportion of the first module is less than 20%.

[0014] Furthermore, the sum of the maximum arc lengths of the third and fourth parting surfaces is less than the minimum value of the inner surface circumference of the annular honeycomb sandwich composite material structure.

[0015] Furthermore, the molding die also includes a block, which is disposed circumferentially at opposite ends of the annular structure and located inside the flange. The block is located below the machining line and its thickness is greater than a set value.

[0016] Furthermore, overflow grooves are provided on the connecting mating surfaces of two adjacent molded bodies.

[0017] Furthermore, the overflow groove is an annular overflow groove.

[0018] Furthermore, each of the said modular bodies has a target point at its end.

[0019] Furthermore, the molding die also includes a support fixture, the main mold body is placed on the upper surface of the support fixture, and the parting mold body is movably disposed on the upper surface of the support fixture.

[0020] Furthermore, the supporting fixture includes a supporting frame, a slide rail, a positioning pin, a limiting block, and a tray. The tray is slidably connected to the upper end face of the supporting frame via the slide rail. The positioning pin is located on the upper end face of the tray and is used to position the corresponding mold part. The limiting block is located on the upper end face of the supporting frame and is used to limit the corresponding mold part.

[0021] (3) Beneficial effects

[0022] In summary, this invention addresses the demolding problem of annular composite material male mold by adopting a split mold body and adding a draft angle to the mold body design. At the same time, it integrates the molding and processing mold of honeycomb sandwich composite materials through detachable side guards. This design and operation method facilitates the production and manufacturing of annular honeycomb sandwich composite material structural parts. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the molding die for a ring-shaped honeycomb sandwich composite material structure provided in an embodiment of the present invention;

[0025] Figure 2 This is a perspective view of the first mold body in a molding die for a ring-shaped honeycomb sandwich composite material structure provided in an embodiment of the present invention;

[0026] Figure 3 This is a top view of the first mold body in a molding die for a ring-shaped honeycomb sandwich composite material structure provided in an embodiment of the present invention;

[0027] Figure 4 This is a front view of the first mold body in a molding die for a ring-shaped honeycomb sandwich composite material structure provided in an embodiment of the present invention;

[0028] Figure 5 This is a right view of the first mold body in a molding die for a ring-shaped honeycomb sandwich composite material structure provided in an embodiment of the present invention;

[0029] Figure 6 This is a schematic diagram of the third mold body in a molding die for a ring-shaped honeycomb sandwich composite material structure provided in an embodiment of the present invention;

[0030] Figure 7 This is a cross-sectional schematic diagram of a molding die for a ring-shaped honeycomb sandwich composite material structure provided in an embodiment of the present invention;

[0031] Figure 8 This is a schematic diagram of the structure of a support fixture for a molding die provided in an embodiment of the present invention;

[0032] Figure 9 This is a schematic diagram of the assembly structure of the main mold body and supporting tooling of a molding die provided in an embodiment of the present invention.

[0033] In the picture:

[0034] 1-Main mold body; 101-First mold body; 102-Second mold body; 103-Third mold body; 104-Fourth mold body; 105-Frame; 106-Side guard; 107-Module; 108-Overflow groove; 109-Target point; 110-Fixing pin; 111-Screw; 112-Positioning pin; 113-Positioning hole; 2-Support fixture; 201-Support frame; 202-Slide rail; 203-Positioning pin; 204-Limiting block; 205-Panel; 3-Annular honeycomb sandwich composite material structural component; A-Machining line. Detailed Implementation

[0035] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present invention by way of example, but should not be used to limit the scope of the present invention. That is, the present invention is not limited to the described embodiments, and any modifications, substitutions and improvements to the parts, components and connection methods are covered without departing from the spirit of the present invention.

[0036] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0037] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0038] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "install" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0039] Figure 1 This is a schematic diagram of the molding die for a ring-shaped honeycomb sandwich composite material structure provided in an embodiment of the present invention, as shown below. Figure 1As shown, the molding die may include a main mold body 1, which includes a frame 105, a retaining edge 106, and at least three parting molds that are detachably connected end to end to form a ring structure. The frame 105 is located inside the ring structure and is used to support each parting mold. The ring structure is provided with retaining edges 106 along the circumferential direction of its opposite ends. At least one parting mold is provided with draft angles along its circumferential and axial directions. The circumferential outer wall of the ring structure is used to lay the prepreg of the annular honeycomb sandwich composite material structure 3.

[0040] In the above embodiment, the main mold body 1 adopts a male mold structure to complete the prepreg laying, honeycomb bonding, and processing. The specific number of parting molds in the ring structure is not limited; too few parts make quick disassembly and demolding difficult, while too many parts make quick installation and disassembly difficult. The male mold surface is designed and formed according to the theoretical internal shape of the structural component, and Invar steel with a low coefficient of thermal expansion and good durability is selected as the material.

[0041] When bonding honeycomb, the removable baffle 106 is installed to prevent the honeycomb from collapsing due to lateral pressure. At the same time, the fixing pin 110 on the baffle 106 can fix the honeycomb to ensure that it does not slip during the bonding curing process.

[0042] As an optional implementation method, such as Figure 1 As shown, the annular structure includes a first mold part 101, a second mold part 102, a third mold part 103 and a fourth mold part 104. The first mold part 101 and the second mold part 102 are symmetrically distributed, and both the first mold part 101 and the second mold part 102 are provided with draft angles along their circumferential and axial directions.

[0043] Specifically, such as Figure 1 As shown, the first mold body 101 is the upper mold body, the second mold body 102 is the lower mold body, the third mold body 103 is the left mold body, and the fourth mold body 104 is the right mold body. The other two parts connected to each part are positioned by positioning pins 112 and screws 111.

[0044] To facilitate demolding of the structural components after molding, the upper mold body of the molding die (such as...) Figure 2-5 As shown), the lower mold body has draft angles in both the circumferential and axial directions. The two mating surfaces of the upper mold body, lower mold body, and adjacent left and right mold bodies form a closed and sealed side structure in the circumferential direction; when the part is packaged, the upper mold body, lower mold body, and the left mold body (as shown) are sealed together. Figure 6 As shown), the mating surfaces between the right and right mold bodies are sealed inside a vacuum bag.

[0045] Specifically, except for the parting body with draft angle, the sum of the maximum arc lengths of the surfaces at the same axial position of the other parting bodies is less than the minimum value of the circumference of the inner surface of the annular honeycomb sandwich composite material structure. This arrangement is to reserve a larger demolding space for the part and facilitate demolding after the part is formed. The sum of the maximum arc lengths of the surfaces of the third parting body 103 and the fourth parting body 104 is less than the minimum value of the circumference of the inner surface of the annular honeycomb sandwich composite material structure 3.

[0046] As an optional implementation, the circumferential proportion of the first mold part 101 is smaller than that of the third mold part 103, and the circumferential proportion of the first mold part 101 is less than 20%. This proportion is selected to facilitate the movement of the heavier mold part under the action of the slide rail 202 of the support fixture 2, ensuring smooth separation of the part from the mold and completing demolding.

[0047] As an optional implementation method, such as Figure 1 As shown, the molding die also includes component 107, such as Figure 7 As shown, multiple modules 107 are located circumferentially at opposite ends of the annular structure and inside the flange 106. Modules 107 are located below machining line A and their thickness is greater than a set value. The detachable modules 107 are designed to process the formed parts without demolding. After removing the modules 107, sufficient machining space is reserved for the machining tools of the machine tool. Therefore, the thickness of the modules 107 is generally not less than 3mm.

[0048] As an optional implementation, overflow grooves 108 are provided on the connecting mating surfaces of two adjacent mold parts, such as... Figure 2 As shown, the overflow groove 108 is an annular overflow groove to prevent the resin from flowing into the screw holes and locating pin holes during the curing process.

[0049] As an optional implementation, each molded part has a target point 109 at its end. For example, Figure 1 As shown, target points 109 are provided on the detachable block 107 and frame 105. The target points 109 are used to assist the projection file to ensure accurate laying of the prepreg and to provide a reference for CNC machining. After the honeycomb bonding is completed, the honeycomb can be shaped and machined without demolding by relying on the target points 109.

[0050] As an optional implementation method, such as Figure 9 As shown, the molding die also includes a support fixture 2. The main mold body 1 is placed on the upper surface of the support fixture 2, and the parting mold body is movably disposed on the upper surface of the support fixture 2. Specifically, the support fixture 2 serves as a support base for the main mold body 1, facilitating the disassembly and separation of the interconnected parting mold bodies. The annular honeycomb sandwich composite material structure 3 is formed on the circumferential outer wall of the main mold body 1.

[0051] As an optional implementation method, such as Figure 8 As shown, the support fixture 2 includes a support frame 201, a slide rail 202, a positioning pin 203, a limiting block 204, and a tray 205. The tray 205 is slidably connected to the upper surface of the support frame 201 via the slide rail 202. The positioning pin 203 is located on the upper surface of the tray 205 and is used to position the corresponding mold part. The limiting block 204 is located on the upper surface of the support frame 201 and is used to limit the corresponding mold part.

[0052] Specifically, such as Figure 1 As shown, the main mold body 1 has positioning holes 113 on its end face that contacts the support fixture 2. Multiple positioning holes 113 are respectively fitted with positioning pins 203 to fix the main mold body 1 to the support fixture 2. After removing the smaller upper and lower mold parts using the draft angle, the left and right mold parts (i.e., the left and right mold parts) are restricted by the limiting block 204. Figure 1 The movement of the third mold body 103 and the fourth mold body 104 in the mold facilitates the separation of the composite parts from the mold.

[0053] The specific process of using this molding die is as follows:

[0054] 1. After assembling and installing the mold body, the prepreg can be laid on the mold surface; when bonding honeycomb, install detachable baffles and set fixing pins at both ends of the mold to prevent lateral pressure from crushing the honeycomb, and fix the honeycomb to ensure that it does not move during the bonding curing period;

[0055] 2. The upper and lower mold bodies are provided with annular overflow grooves on their mating surfaces that connect with the left and right mold bodies to prevent resin from flowing into the screw holes and locating pin holes during curing;

[0056] 3. The target points of the mold are used to assist the projection file in ensuring accurate prepreg placement, and at the same time provide a reference for CNC machining;

[0057] 4. After the honeycomb sandwich composite material structural component is formed, the modules are removed, and the composite material structural component is processed along the machining line;

[0058] 5. When demolding the composite material, the molding fixture is placed horizontally on the support fixture with the help of positioning holes and positioning pins; the upper and lower mold bodies of the molding fixture are disassembled first with the help of the draft angle, and then the left and right mold bodies are closed together with the help of the movable slide rail on the support fixture, so as to further remove the ring composite material structure and complete the demolding.

[0059] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. Furthermore, for the sake of brevity, detailed descriptions of known methods and techniques are omitted here.

[0060] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art without departing from the scope of the invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A molding die for a ring-shaped honeycomb sandwich composite material structure, characterized in that, The system includes a main mold body (1), which includes a frame (105), a retaining edge (106), and at least three sub-mold bodies that are detachably connected end to end to form a ring structure. The frame (105) is located inside the ring structure and is used to support each sub-mold body. The retaining edge (106) is located at the circumferential direction at opposite ends of the ring structure. At least one sub-mold body has a draft angle along its circumferential and axial directions. The circumferential outer wall of the ring structure is used to lay the prepreg of the annular honeycomb sandwich composite material structure (3). It also includes a block (107) which is located circumferentially at opposite ends of the annular structure and inside the flange (106). The block (107) is located below the machining line and its thickness is greater than a set value.

2. The molding die for the annular honeycomb sandwich composite material structure according to claim 1, characterized in that, The annular structure includes a first mold part (101), a second mold part (102), a third mold part (103), and a fourth mold part (104). The first mold part (101) and the second mold part (102) are symmetrically distributed. The first mold part (101) and the second mold part (102) are provided with the draft angle along their circumferential and axial directions.

3. The molding die for the annular honeycomb sandwich composite material structure according to claim 2, characterized in that, The circumferential proportion of the first module (101) is smaller than the circumferential proportion of the third module (103).

4. The molding die for the annular honeycomb sandwich composite material structure according to claim 2, characterized in that, The circumferential proportion of the first module (101) is less than 20%.

5. The molding die for the annular honeycomb sandwich composite material structure according to claim 2, characterized in that, The sum of the maximum arc lengths of the third and fourth sub-modules (103) is less than the minimum circumference of the inner surface of the annular honeycomb sandwich composite material structure (3).

6. The molding die for the annular honeycomb sandwich composite material structure according to claim 1, characterized in that, An overflow groove (108) is provided on the connecting mating surface of two adjacent mold parts.

7. The molding die for the annular honeycomb sandwich composite material structure according to claim 1, characterized in that, Each of the said modular bodies has a target point (109) at its end.

8. The molding die for the annular honeycomb sandwich composite material structure according to claim 1, characterized in that, It also includes a support fixture (2), the main mold body (1) is placed on the upper surface of the support fixture (2), and the mold part is movably disposed on the upper surface of the support fixture (2).

9. The molding die for the annular honeycomb sandwich composite material structure according to claim 8, characterized in that, The supporting fixture (2) includes a supporting frame (201), a slide rail (202), a positioning pin (203), a limiting block (204), and a tray (205). The tray (205) is slidably connected to the upper surface of the supporting frame (201) via the slide rail (202). The positioning pin (203) is located on the upper surface of the tray (205) and is used to position the corresponding mold part. The limiting block (204) is located on the upper surface of the supporting frame (201) and is used to limit the corresponding mold part.

Images