Process method capable of achieving molding and assembling integration of composite material support

Abstract

The invention belongs to the technical field of composite material forming, and relates to a forming and assembling integrated process method for a composite material support. The method comprises the steps that the composite material support is divided into an upper mounting plate, a lower mounting plate and side face supporting columns, and functional area parts of the upper mounting plate and the lower mounting plate are of grid structures; grid structures of the upper mounting plate and the lower mounting plate are formed; forming side supporting pillars; and the formed grating structures of the upper mounting plate and the lower mounting plate and the side face supporting columns are installed in an upper plate forming mold and a lower plate forming mold, and integrated forming of the upper mounting plate, the lower mounting plate and the side face supporting columns is carried out. Parting is carried out according to the structure of the composite material support, the applicable tool mold and the forming method are designed according to different structural characteristics of the parted product, the production efficiency can be improved while the structural strength of the product is guaranteed, and the production cost is reduced.

Description

Technical Field

[0001] The invention relates to a process method for integrating molding and assembling of a composite material bracket, belonging to the technical field of composite material molding. Background Art

[0002] Composite materials have excellent mechanical properties such as high specific stiffness and specific strength, good fatigue resistance and corrosion resistance, and have been widely used in aviation, aerospace and other fields. Compared with aluminum alloy brackets, composite brackets of the same structure have lower weight, greater load bearing and higher structural efficiency.

[0003] However, due to the special use of composite brackets, they have many openings and complex structures. If the integral molding method is adopted, the workload of laying layers is large, the assembly and demoulding are difficult, and the production time is long. In order to simplify the process and improve production efficiency, a composite bracket molding and assembly method is proposed, which can realize the rapid molding and assembly of multi-layer composite brackets. Summary of the invention

[0004] The purpose of the present invention is to classify the structure of a composite material bracket, and to design a suitable tooling mold and molding method according to different structural characteristics of the product after classification, so as to ensure the structural strength of the product while improving production efficiency and reducing production costs.

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

[0006] A process method for realizing integrated molding and assembly of a composite material bracket comprises the following steps:

[0007] The composite material bracket is divided into an upper mounting plate, a lower mounting plate and a side support pillar, wherein the functional area of ​​the upper mounting plate and the lower mounting plate is a grid structure;

[0008] forming a grille structure of an upper mounting plate and a lower mounting plate;

[0009] molded side support struts;

[0010] The grille structures and side support pillars of the formed upper mounting plate and lower mounting plate are installed in the upper plate forming mold and the lower plate forming mold to perform integrated forming of the upper mounting plate, the lower mounting plate and the side support pillars.

[0011] Furthermore, the reinforcing fiber used in the composite bracket is carbon fiber or glass fiber, the upper mounting plate and the lower mounting plate use glass fiber, the side support pillars use carbon fiber, or the upper mounting plate, the lower mounting plate and the side support pillars all use glass fiber or carbon fiber.

[0012] Furthermore, the composite material bracket adopts a resin that is cured at room temperature or low temperature or medium or high temperature, and the resin is epoxy resin, bismaleimide resin, phenolic resin or polyimide resin.

[0013] Furthermore, the side support struts are a composite solid structure, or a sandwich structure composed of a composite skin and a weight-reducing core layer.

[0014] Furthermore, the grid structure includes a plane grid formed by the intersection of transverse ribs and longitudinal ribs.

[0015] Furthermore, the forming step of the grid structure includes: forming a long tube by winding or pultrusion process, and then cutting the long tube into multiple frames along the length direction, and combining the multiple frames by adhesive or high resin content prepreg to form a grid.

[0016] Furthermore, the composite material bracket includes four side support struts, and the side support struts include side support struts with weight reduction grooves and side support struts without weight reduction grooves; the side support struts with weight reduction grooves are formed by a template stacking and lamination method, and the side support struts without weight reduction grooves are formed by a winding and lamination method on a foam core material.

[0017] Furthermore, the integrated molding of the upper mounting plate, the lower mounting plate and the side supporting pillars includes: combining the upper mounting plate, the lower mounting plate and the side supporting pillars by means of an adhesive, and curing and molding the combined upper mounting plate, the lower mounting plate and the side supporting pillars.

[0018] Furthermore, the integrated forming of the upper mounting plate, the lower mounting plate and the side support pillars includes:

[0019] Place the cut grid frames into the upper plate forming mold and the lower plate forming mold for assembly, bond the adjacent frames, and lay up the upper and lower mounting plates except the grid with carbon fiber / epoxy resin prepreg. After the laying is completed, install the top molds of the upper plate forming mold and the lower plate forming mold on the bottom mold, and fix the top mold and the bottom mold so that the gap between the top mold and the bottom mold is less than 0.10mm.

[0020] Bond the butt joint surfaces of the lateral support pillar and the upper mounting plate and the lower mounting plate, then butt joint the lateral support pillar and the lower plate forming mold, install the assembly tooling guide pillar on the lower plate forming mold, install the upper plate forming mold on the assembly tooling guide pillar, and butt joint the lateral support pillar and the upper plate forming mold;

[0021] The upper plate forming mold and the lower plate forming mold are moved into an oven for curing and forming.

[0022] The present invention also provides a composite material bracket formed according to the method.

[0023] The beneficial effects of the present invention are as follows:

[0024] Through actual production verification, the product production time of the present invention is reduced by nearly 50% compared with the overall molding solution. Due to the significant reduction in labor cost, the production cost of the present invention is reduced by 32.7% compared with the overall molding solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural diagram of the composite material bracket.

[0026] Figure 2 This is a parting diagram of the composite material bracket.

[0027] Figure 3 This is a diagram of the side support pillar molding.

[0028] Figure 4 It is a structural diagram of the bracket assembly combination tooling.

[0029] Figure 5 It is the parting drawing of the bracket assembly tooling. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below through specific embodiments and drawings.

[0031] The present invention divides the composite material bracket into a functional area and a supporting area first, and then performs secondary molding on the functional area and the supporting area. Parts with large thickness and complex layering adopt a solution of pre-molding a flat plate and then machining. Parts with the same size characteristics adopt a one-mold-multiple-piece process solution. The components are finally assembled and combined through high-resin content prepreg or adhesive. The size accuracy and spatial position of each component of the bracket are guaranteed by a molding mold and an assembly combination mold.

[0032] like Figure 1 , Figure 2 As shown, the composite material bracket 10 can be divided into an upper mounting plate 20 , a lower mounting plate 30 , and side supporting pillars 40 , 50 , 60 , 70 .

[0033] The composite material bracket 10 uses carbon fiber or glass fiber as reinforcing fiber. According to the required stiffness, strength index and weight index, and the comprehensive product cost consideration, glass fiber can be used in the upper mounting plate 20 and the lower mounting plate 30, and carbon fiber can be used in the side support pillars 40 to 70, or all glass fiber or carbon fiber can be used.

[0034] The composite material bracket 10 may be made of a resin that cures at room temperature or at medium or high temperature, depending on the use environment. The resin may be epoxy resin, bismaleimide resin, phenolic resin or polyimide resin.

[0035] The functional area of ​​the upper mounting plate 20 and the lower mounting plate 30 of the composite material bracket 10 is usually a grid structure. The plane grid formed by the cross-ribs and longitudinal ribs of the grid is used to adapt to the installation of products and play the role of the bracket.

[0036] The side support pillars 40 to 70 of the composite material bracket 10 can be a composite material solid structure or a sandwich structure composed of a composite material skin and a weight-reducing core layer, depending on different load-bearing, weight and cost requirements.

[0037] The grid structure of the upper mounting plate 20 and the lower mounting plate 30 of the composite material bracket 10 is usually made by the following method: a long tube is formed by winding or pultrusion process, and then cut into a plurality of narrow sections along the height direction (the length direction of the long tube). The plurality of cut sections are combined by adhesive or high resin content prepreg to form a grid.

[0038] The composite material bracket 10, the upper mounting plate 20, the lower mounting plate 30 and the side support pillars 40-70 are combined by adhesive, the adhesive can be cured at room temperature or medium-high temperature, and the dimensional accuracy of the combined product is guaranteed by the assembly tool. The assembly tool of the composite material bracket can realize the integrated bonding and curing molding of the upper mounting plate, the lower mounting plate and the side support pillars, and can also realize the bonding and curing assembly of the upper mounting plate and the lower mounting plate separately and then bonding and forming with the side support pillars.

[0039] In one embodiment of the present invention, forming a composite material bracket product includes the following steps:

[0040] The composite material bracket is divided into an upper mounting plate, a lower mounting plate and a side support pillar, wherein the functional area of ​​the upper mounting plate and the lower mounting plate is a grid structure;

[0041] forming a grille structure of an upper mounting plate and a lower mounting plate;

[0042] molded side support struts;

[0043] The grille structures and side support pillars of the formed upper mounting plate and lower mounting plate are installed in the upper plate forming mold and the lower plate forming mold to perform integrated forming of the upper mounting plate, the lower mounting plate and the side support pillars.

[0044] In one embodiment of the present invention, the grid structure of the molded upper mounting plate and the lower mounting plate comprises:

[0045] Place the carbon fiber / epoxy resin prepreg onto the automatic slitting platform for winding and slitting;

[0046] Clean the grid winding mold and apply the release agent. After the release agent becomes a uniform and transparent film, hoist the winding mold onto the auxiliary device of the winding machine.

[0047] The die end face is used as the winding starting point. The winding end position is determined according to the starting position and winding length. The winding parameters are set, including winding length, number of winding layers, whether to stop between layers, winding radius, winding tension, yarn width, etc.

[0048] Debug the winding machine and return it to the origin. The carbon fiber / epoxy resin prepreg tape passes through the guide roller. Call up the program, input the starting and ending positions, and start the winding program.

[0049] Heat the prepreg tape, wind it according to the procedure, and cut the prepreg tape after completing one cycle;

[0050] The wrapped prepreg tape is packaged with a non-porous film, breathable felt and vacuum bag in turn, sealed with a sealing strip and then vacuumed, and finally the product is pushed into an autoclave for curing;

[0051] The solidified product is cut on a machine tool into square frames.

[0052] In one embodiment of the present invention, the molded side support pillar comprises:

[0053] Each composite bracket includes four side support struts, including side support struts with weight reduction grooves and side support struts without weight reduction grooves; the side support struts with weight reduction grooves are formed by a sample stacking and lamination method, and the side support struts without weight reduction grooves are formed by a winding and lamination method on a foam core material.

[0054] In one embodiment of the present invention, the integrated molding of the upper mounting plate, the lower mounting plate and the side supporting pillars includes: combining the upper mounting plate, the lower mounting plate and the side supporting pillars by means of an adhesive, and curing and molding the combined upper mounting plate, the lower mounting plate and the side supporting pillars.

[0055] In one embodiment of the present invention, the integrated forming of the upper mounting plate, the lower mounting plate and the side support pillars includes:

[0056] Place the cut grid frames into the upper plate forming mold and the lower plate forming mold for assembly, bond the adjacent frames, and lay up the upper and lower mounting plates except the grid with carbon fiber / epoxy resin prepreg. After the laying is completed, install the top molds of the upper plate forming mold and the lower plate forming mold on the bottom mold, and fix the top mold and the bottom mold so that the gap between the top mold and the bottom mold is less than 0.10mm.

[0057] Bond the butt joint surfaces of the lateral support pillar and the upper mounting plate and the lower mounting plate, then butt joint the lateral support pillar and the lower plate forming mold, install the assembly tooling guide pillar on the lower plate forming mold, install the upper plate forming mold on the assembly tooling guide pillar, and butt joint the lateral support pillar and the upper plate forming mold;

[0058] The upper plate forming mold and the lower plate forming mold are moved into an oven for curing and forming.

[0059] In one embodiment of the present invention, a complete process for forming a composite material bracket product is provided, including the following steps:

[0060] The first step is to form the upper and lower mounting plate grille structure.

[0061] Place the T700 grade carbon fiber / 9368 epoxy resin prepreg on the automatic slitting platform for winding. Set the width to 110 mm, the wide band coefficient to 0.125, the automatic speed to 1000, the manual speed to 800, and then slitting.

[0062] Clean the grid winding mold and apply Ken-Tian 255 release agent. After the release agent becomes a uniform and transparent film, hoist the winding mold onto the auxiliary device of the winding machine.

[0063] The die end face is used as the winding starting point, and the winding end position is determined according to the starting point position and the winding length. The winding length is about 400mm; the number of winding layers: 1; whether to stop between layers (0 / 1): 1; winding radius (mm): 850; winding tension (N): 180; yarn sheet width (mm): 1.4.

[0064] Debug the winding machine back to the origin, pass the 110mm wide T700 grade carbon fiber / 9368 epoxy resin prepreg tape through the guide roller, call up the program, enter the starting and end positions, and start the winding program.

[0065] Start the hot roller at the wire nozzle to heat the prepreg tape, and the heating temperature is controlled at 90-110°C; wind it according to the procedure, and cut the prepreg tape after completing one cycle.

[0066] The wrapped prepreg tape is packaged with a non-porous film, breathable felt and vacuum bag in turn, sealed with a sealing strip and vacuumed, and finally the product is pushed into the autoclave for curing. The curing parameters are set as follows: room temperature → start heating (fixed temperature 90℃, start pressurization) → 100℃±10℃ → pressurize to 0.5MPa → heating (fixed temperature 130℃) → 120℃±10℃ → pressurize to 0.8MPa, keep warm for 2h, turn off heating, slowly release pressure → cool down to below 50℃ (cooling rate should be less than 2℃ / min) and take out of the can.

[0067] The solidified product is cut on a machine tool into two sizes of square frames with heights of 15 mm and 30 mm. The two sizes of square frames are used to form the upper mounting plate and the lower mounting plate respectively.

[0068] The second step is to form the side support pillars.

[0069] Each bracket has four pillars on the side to realize structural bearing. The pillars have two structures, one with weight-reducing grooves and the other without weight-reducing grooves.

[0070] Use an automatic cloth cutting machine to cut the pillar templates and lay the cut pillar templates in the mold in order, such as Figure 3 As shown, the side support pillar forming mold is divided into a top mold 101 and a bottom mold 102, and 103 in the figure is a side support pillar. Among them, the pillar with a weight-reducing groove structure adopts a sample plate stacking solution, and the pillar without a weight-reducing groove structure adopts a solution of winding and laying on the foam core material.

[0071] After the product is laid, move the mold into the press and place a 2mm gasket between the top and bottom molds of the mold. Set the press temperature to 110℃, and when the mold temperature reaches 90℃, pressurize it by 3MPa-5MPa, wait for 3min and continue to pressurize it, so that the gap between the top and bottom molds is less than 0.10mm. Set the press temperature to 140℃, wait for the mold to heat up to (130±5)℃, keep it warm for 120min, and then naturally cool it down to below 50℃.

[0072] The third step is to bond the upper and lower mounting plates and assemble the upper and lower mounting plates and the side support pillars into an integrated form.

[0073] like Figure 4 , Figure 5As shown, the grid frame cut in the first step is placed in the upper and lower plate molds (including the upper plate forming mold 201 and the lower plate forming mold 202) for assembly. A layer of J-47B glue is evenly brushed on the butt joint surface of adjacent frames. After airing for (20-30) minutes, a layer of J-47A glue mold is attached. The other areas of the upper and lower mounting plates except the grid are layered with T700 grade carbon fiber / 9368 medium temperature epoxy resin prepreg. After the layering is completed, the top molds of the upper and lower plate forming molds are respectively installed on the bottom molds, that is, the top mold 2011 of the upper plate forming mold 201 is installed on the bottom mold 2012, and the top mold 2021 of the lower plate forming mold 202 is installed on the bottom mold 2022, and the top mold and the bottom mold are tightened with screws so that the gap between the top mold and the bottom mold is less than 0.10mm.

[0074] Apply a layer of J-47B glue evenly on the butt joint surface of the lateral support pillar 203 and the upper and lower mounting plates, let it dry for (20-30) minutes, and then apply a layer of J-47A glue mold. Then butt joint the lateral support pillar 203 with the installed lower plate forming mold 202, install the assembly tooling guide pillar 204 on the lower plate forming mold, and finally install the upper plate forming mold on the assembly tooling guide pillar 204, so that the lateral support pillar 203 and the upper plate forming mold 201 are butt jointed, and the assembly of the product and the bracket assembly tooling is completed.

[0075] Move the mold into the oven and set the oven temperature to 175℃. When the mold temperature rises to 130℃±5℃, set the oven temperature to 145℃ and keep it warm for 2h. Then naturally cool the mold to below 50℃ for demoulding to complete product curing.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A process method for realizing integrated molding and assembly of a composite material bracket, characterized in that: The following steps are involved: The composite material bracket is divided into an upper mounting plate, a lower mounting plate and a side support pillar, wherein the functional area of ​​the upper mounting plate and the lower mounting plate is a grid structure; forming a grille structure of an upper mounting plate and a lower mounting plate; molded side support struts; The grille structures and side support pillars of the formed upper mounting plate and lower mounting plate are installed in the upper plate forming mold and the lower plate forming mold to perform integrated forming of the upper mounting plate, the lower mounting plate and the side support pillars.

2. The method according to claim 1, characterized in that The reinforcing fiber used in the composite material bracket is carbon fiber or glass fiber. Glass fiber is used in the upper mounting plate and the lower mounting plate, and carbon fiber is used in the side supporting pillars, or the upper mounting plate, the lower mounting plate and the side supporting pillars are all made of glass fiber or carbon fiber.

3. The method according to claim 1, characterized in that The composite material bracket adopts a resin that is cured at room temperature and low temperature or medium and high temperature, and the resin is epoxy resin, bismaleimide resin, phenolic resin or polyimide resin.

4. The method according to claim 1, characterized in that: The side support pillar is a composite solid structure, or a sandwich structure composed of a composite skin and a weight-reducing core layer.

5. The method according to claim 1, characterized in that The grid structure includes a plane grid formed by the intersection of transverse ribs and longitudinal ribs.

6. The method according to claim 1, characterized in that The forming steps of the grid structure include: forming a long tube by winding or pultrusion process, then cutting the long tube into multiple frames along the length direction, and combining the multiple frames by adhesive or high resin content prepreg to form a grid.

7. The method according to claim 1, characterized in that The composite material bracket includes four side support struts, and the side support struts include side support struts with weight reduction grooves and side support struts without weight reduction grooves; the side support struts with weight reduction grooves are formed by a template stacking and laminating method, and the side support struts without weight reduction grooves are formed by a winding and laminating method on a foam core material.

8. The method according to claim 1, characterized in that The integrated molding of the upper mounting plate, the lower mounting plate and the side supporting pillars includes: combining the upper mounting plate, the lower mounting plate and the side supporting pillars by means of an adhesive, and curing and molding the combined upper mounting plate, the lower mounting plate and the side supporting pillars.

9. The method according to claim 1, characterized in that: The integrated forming of the upper mounting plate, the lower mounting plate and the side support pillars includes: Place the cut grid frames into the upper plate forming mold and the lower plate forming mold for assembly, bond the adjacent frames, and lay up the upper and lower mounting plates except the grid with carbon fiber / epoxy resin prepreg. After the laying is completed, install the top molds of the upper plate forming mold and the lower plate forming mold on the bottom mold, and fix the top mold and the bottom mold so that the gap between the top mold and the bottom mold is less than 0.10mm. Bond the butt joint surfaces of the lateral support pillar and the upper mounting plate and the lower mounting plate, then butt joint the lateral support pillar and the lower plate forming mold, install the assembly tooling guide pillar on the lower plate forming mold, install the upper plate forming mold on the assembly tooling guide pillar, and butt joint the lateral support pillar and the upper plate forming mold; The upper plate forming mold and the lower plate forming mold are moved into an oven for curing and forming.

10. A composite material bracket formed according to the method of any one of claims 1 to 9.

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