Manufacturing method of composite apron board

Abstract

The invention discloses a composite material apron board manufacturing method, and relates to the technical field of passenger train bodies, the manufacturing method comprises the following steps: S1, cutting an apron board blanking based on a two-dimensional electronic drawing of design requirements; s2, coating a release agent layer on the inner surface of a mold required for shaping the apron board; s3, an isolating membrane is laid on the surface of the core mold, core mold prefabricated bodies are prepared, the two core mold prefabricated bodies are combined, the outer cladding material pieces are laid on the surfaces of the two core mold prefabricated bodies, and a combined prefabricated body is formed; s4, the combined prefabricated body separated from the core mold is put into the upper mold and the lower mold, and then a combined material is laid; s5, the mold is sealed, and then a curing oven is used for heating and curing; s6, the cured part is taken out of the mold for demolding; and S7, the cured finished part obtained after demolding is cut. By means of integral forming and one-time curing, the debonding risk does not exist, the overall performance is better than that of secondary bonding, the machining cost of an engraving machine, the bonding assembly time and the bonding curing cost are saved, and the overall manufacturing cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of railway passenger car bodies, and in particular to a method for manufacturing a composite material skirt plate. Background Art

[0002] With the increase in the operating speed of rail trains and the requirements for energy conservation and emission reduction, lightweight design is constantly pursued in vehicle design. However, conventional metal materials are currently difficult to meet the contradiction between performance and weight. In order to solve this problem, more and more composite materials are being used in rail vehicles. Composite materials have the characteristics of light weight, high strength, chemical corrosion resistance and good weather resistance, and have been widely used in train skirts, equipment compartments, driver's cab hoods and other components.

[0003] At present, on rail vehicles, composite skirt structures are mainly skin-reinforced structures, foam or honeycomb sandwich structures, and multi-cavity structures. The mainstream manufacturing processes usually use hand lay-up and autoclave molding. The hand lay-up process has strong applicability, but it is easy to cause a high void ratio and resin content, and the product thickness is difficult to control, resulting in unstable product performance and greatly limiting product application; while the autoclave molding process has the advantages of uniform resin content, dense internal structure and good internal quality, but the high manufacturing cost makes it difficult to promote and apply it on rail transit vehicles.

[0004] For example, Chinese patent CN105500837B discloses a process for making a high-speed rail equipment compartment skirt panel from composite materials. The skirt panel is a honeycomb sandwich structure, which is formed in steps and finally assembled by gluing. This process method has a risk of debonding between the steps due to the large number of forming steps, and the honeycomb core and adhesive film used in the method increase the material and processing costs.

[0005] Another example is Chinese patent CN111823610B, which discloses a method for manufacturing composite body skirts. This method adopts OOA molding process. The main technical feature is that the material is laid on the inner and outer molds, and then cured in a curing furnace after the molds are closed. A metal inner mold is used to replace the silicone rubber inner mold in the original technical solution, which reduces the cost. In this method, the molding process is pressurized to vacuum pressure, and the pressure is relatively low. This method has high requirements on the materials used. It is necessary to use prepregs specially used for OOA molding. There are few mature materials in China. If this material is not used, it is difficult to obtain good internal quality of the parts.

[0006] Therefore, how to provide a method for manufacturing a composite material vehicle body skirt that can reduce costs and ensure product manufacturing quality is a problem that technical personnel in this field urgently need to solve. Summary of the invention

[0007] Based on this, it is necessary to provide a method for manufacturing a composite material skirt panel in response to the above technical problems.

[0008] The present invention provides a method for manufacturing a composite material skirt plate, the manufacturing method comprising: S1. Cut the skirt board based on the two-dimensional electronic drawings required by the design; S2. Coating a release agent layer on the inner surface of the mold required for shaping the skirt plate; S3, laying an isolation film on the surface of the core mold to prepare a core mold preform, and combining two core mold preforms, laying outer cladding sheets on the surfaces of both to form a combined preform; S4, placing the combined preform that escapes from the core mold into the upper and lower molds, and then laying the combined materials; S5, sealing the mold, and then heating and curing it in a curing furnace; S6, taking out the cured part from the mold for demoulding; S7, cutting the cured parts after demoulding to obtain the finished composite material skirt board.

[0009] Further, laying an isolation film on the surface of the core mold to prepare a core mold preform, and combining two core mold preforms, laying outer cladding sheets on the surfaces of both, to form a combined preform includes the following steps: S31, selecting two core molds of different shapes; S32, laying an isolation film on the surface of the core mold and attaching it tightly by vacuuming; S33, laying the inner cavity coating layer sheets on the surface of the core mold in sequence until the laying is completed to form an inner cavity coating layer laying group, and obtain a core mold preform; S34, filling yarn in the R angle triangle area based on the equal cross-section calculation of the two core mold preforms; S35, assembling and mounting the two core mold preforms on a rotating fixture, and laying the outer cladding sheets on the outer surfaces of the two core mold preforms in sequence by rotation until the laying is completed to form an outer cladding fiber ply group, thereby obtaining a combined preform.

[0010] Furthermore, the core mold includes a triangular paving core mold and a rectangular paving core mold, and the triangular paving core mold and the rectangular paving core mold are combined to form a skirt board structure.

[0011] Further, based on the equal cross-section calculation of the two core mold preforms, filling yarn in the R angle triangle area includes the following steps: S341, obtaining the R angle position formed between the two core mold preforms, obtaining the equal cross-section of the core mold preform, and measuring the shape parameters of the R angle triangle area; S342, converting density to volume based on known fiber density, calculating the filling amount in the R-angle triangle area, and then selecting filling materials to fill the corresponding positions.

[0012] Furthermore, during the laying process of the inner cavity coating layer laying group and the outer cladding fiber layer laying group, vacuum compaction is performed once every 2-6 layers until 9 layers are laid.

[0013] Further, placing the combined preform out of the core mold into the upper and lower molds and then laying the combined material comprises the following steps: S41, removing the core mold from the two core mold preforms; S42, placing the combined preform in the upper mold and the lower mold of the mold for mold closing, and placing a sealing strip between the upper mold and the lower mold to eliminate the mold closing gap; S43, lay the combined materials in the mold cavity in order, bag and seal them, and test the air tightness.

[0014] Furthermore, the combined materials include a release cloth, a porous isolation membrane, a breathable felt and a vacuum bag film, and the laying order is the release cloth, the porous isolation membrane, the breathable felt and the vacuum bag film.

[0015] Further, the mold is sealed and then heated and cured in a curing furnace, which includes the following steps: S51, installing the side metal plate of the mold, sealing and fixing the mold, so that the air nozzle on the side metal plate and the vacuum bag film form a sealed cavity; S52, placing the mold into a curing furnace for heating and curing, and connecting the air nozzle on the metal plate on the side of the mold to control the curing pressure inside the mold by compressed air until the curing is completed.

[0016] Furthermore, the curing pressure is 0.3MPa-0.6Mpa.

[0017] Further, removing the cured part from the mold for demoulding includes the following steps: S61, removing the side metal plate of the mold, and taking out the cured part by demoulding; S62, cooling the cured part to room temperature, removing the mold, and removing the auxiliary materials.

[0018] The beneficial effects of the present invention are: 1. By adopting integral molding and one-time curing, there is no risk of debonding, and the overall performance is better than that of secondary bonding. In terms of cost, the present invention does not require honeycomb costs, does not require film costs, and only requires prepregs required for structural parts. At the same time, it saves engraving machine processing, bonding assembly time and bonding curing costs, and the overall manufacturing cost is reduced; at the same time, the present invention uses compressed air to pressurize the prepreg, and the pressure is much greater than the vacuum pressure, which can effectively ensure the internal quality.

[0019] 2. By adopting an external rigid mold, the product can be guaranteed to have accurate size and beautiful appearance. At the same time, compressed air is used for pressurization, and the product cavity is bagged. Vacuum pressure is applied to the product and compressed air is used for pressurization to ensure quality, effectively improve the convenience of operation, and reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 is a flow chart of a method for manufacturing a composite material skirt panel according to an embodiment of the present invention; Figure 2 is a schematic isometric cross-sectional view of a composite material skirt according to an embodiment of the present invention; Figure 3 is one of the structural schematic diagrams of a mold according to an embodiment of the present invention; Figure 4 This is a second structural schematic diagram of a mold according to an embodiment of the present invention; Figure 5 is a schematic structural diagram of a rotary tooling according to an embodiment of the present invention; Figure 6 is an isometric cross-sectional schematic diagram of a mold according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0022] See also Figure 1 , provides a method for manufacturing a composite skirt panel, the manufacturing method comprising: S1. Cut the skirt board based on the two-dimensional electronic drawing required by the design.

[0023] S2. Coat a release agent layer on the inner surface of the mold required for shaping the skirt plate.

[0024] Among them, the structure of the mold is as follows Figure 3 and Figure 4 As shown, Figure 3 and Figure 4 The numbers and names of the structures are: 201-upper die, 202-die bolts, 203-lower die, 204-die sealing groove, 205-air nozzle and 206-side metal mounting plate.

[0025] S3, laying an isolation film on the surface of the core mold to prepare a core mold preform, and combining two core mold preforms, laying outer cladding sheets on the surfaces of both, to form a combined preform.

[0026] In the description of the present invention, laying an isolation film on the surface of the core mold to prepare a core mold preform, and combining two core mold preforms, laying outer cladding sheets on the surfaces of both, to form a combined preform includes the following steps: S31. Select two core molds of different shapes.

[0027] In the description of the present invention, the core mold includes a triangular paving core mold and a rectangular paving core mold, and the triangular paving core mold and the rectangular paving core mold are combined to form a skirt board structure.

[0028] S32, laying an isolation film on the surface of the core mold and attaching it tightly by vacuuming.

[0029] S33, laying the inner cavity coating layer sheets on the surface of the core mold in sequence until the laying is completed to form an inner cavity coating layer laying group and obtain a core mold preform.

[0030] S34. Fill the R-angle triangle area with yarn based on the equal cross-section calculation of the two core mold preforms.

[0031] In the description of the present invention, based on the equal cross-section calculation of two core mold preforms, filling yarn in the R angle triangle area includes the following steps: S341, obtaining the R angle position formed between the two core mold preforms, obtaining the equal cross-section of the core mold preform, and measuring the shape parameters of the R angle triangle area.

[0032] S342, converting density to volume based on known fiber density, calculating the filling amount in the R-angle triangle area, and then selecting filling materials to fill the corresponding positions.

[0033] S35, assembling and mounting the two core mold preforms on a rotating fixture, and laying the outer cladding sheets on the outer surfaces of the two core mold preforms in sequence by rotation until the laying is completed to form an outer cladding fiber ply group, thereby obtaining a combined preform.

[0034] Specifically, the structure of the rotary tooling is as follows Figure 5 As shown, the numbers and names of the various structures in the figure are respectively: 301, 304-skirt panel inner cavity covering layer laying group paving core mold (including triangular paving core mold and rectangular paving core mold), 302, 303-core mold positioning and rotating tooling, 305-tooling bracket.

[0035] In the description of the present invention, during the laying process of the inner cavity coating layer laying group and the outer cladding fiber layer laying group, vacuum compaction is performed once every 2-6 layers until 9 layers are laid.

[0036] S4, placing the combined preform that has escaped from the core mold into the upper and lower molds, and then laying the combined materials.

[0037] In the description of the present invention, placing the combined preform out of the core mold into the upper and lower molds and then laying the combined material includes the following steps: S41, removing the core mold from the two core mold preforms; S42, placing the combined preform in the upper mold and the lower mold of the mold for mold closing, and placing a sealing strip between the upper mold and the lower mold to eliminate the mold closing gap; S43, lay the combined materials in the mold cavity in order, bag and seal them, and test the air tightness.

[0038] In the description of the present invention, the combined materials include a release cloth, a porous isolation film, a breathable felt and a vacuum bag film, and the laying order is the release cloth, the porous isolation film, the breathable felt and the vacuum bag film.

[0039] S5. The mold is sealed and then heated and cured in a curing furnace.

[0040] In the description of the present invention, the mold is sealed and then heated and cured in a curing furnace, which includes the following steps: S51. Install the side metal plate of the mold, seal and fix the mold, so that the air nozzle on the side metal plate and the vacuum bag film form a sealed cavity to prevent air leakage.

[0041] S52, placing the mold into a curing furnace for heating and curing, and connecting the air nozzle on the metal plate on the side of the mold to control the curing pressure inside the mold by compressed air until the curing is completed.

[0042] In the description of the present invention, the curing pressure is 0.3MPa-0.6MPa.

[0043] S6. Take out the cured part from the mold and demould it.

[0044] In the mold, the skirt is cured and shaped, such as Figure 6 As shown, in the figure, 1 represents a composite material skirt plate, and the skirt plate can be ensured to complete stable heating and curing through the shaping of the upper mold and the lower mold.

[0045] In the description of the present invention, removing the cured finished part from the mold for demoulding includes the following steps: S61. Remove the side metal plate of the mold and take out the cured part by demoulding.

[0046] S62, cooling the cured part to room temperature, removing the mold, and removing the auxiliary materials.

[0047] S7, cutting the cured parts after demoulding to obtain the finished composite material skirt board.

[0048] Specifically, the finished skirt structure is as follows Figure 2 As shown, the numbers and names of the parts in the figure are: 101 - outer cladding fiber ply group, 102, 103 - inner cavity cladding layer ply group, 104, 105, 106 - R angle triangle area filling yarn.

[0049] In summary, with the help of the above technical scheme of the present invention, by adopting integral molding and one-time curing, there is no risk of debonding, and the overall performance is better than secondary bonding. In terms of cost, the present invention does not require honeycomb costs, does not require film costs, and only requires prepregs required for structural parts. At the same time, it saves engraving machine processing, bonding assembly time and bonding curing costs, and the overall manufacturing cost is reduced; at the same time, the present invention uses compressed air pressurization to apply pressure to the prepreg, and the pressure is much greater than the vacuum pressure, which can effectively ensure the internal quality. By adopting an external mold rigid mold, the product size can be guaranteed to be accurate and the appearance can be beautiful; at the same time, compressed air pressurization is used to bag the inside of the product cavity, and vacuum pressure is applied to the product and compressed air pressurization is used to ensure quality, and effectively improve the convenience of operation and reduce costs.

[0050] It should be understood that, although the steps in the flowchart of the accompanying drawings are displayed in sequence as indicated by the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

Claims

1. A method for manufacturing a composite material skirt panel, characterized in that: The manufacturing method comprises: S1. Cut the skirt board based on the two-dimensional electronic drawings required by the design; S2. Coating a release agent layer on the inner surface of the mold required for shaping the skirt plate; S3, laying an isolation film on the surface of the core mold to prepare a core mold preform, and combining two core mold preforms, laying outer cladding sheets on the surfaces of both to form a combined preform; S4, placing the combined preform that escapes from the core mold into the upper and lower molds, and then laying the combined materials; S5, sealing the mold, and then heating and curing it in a curing furnace; S6, taking out the cured part from the mold for demoulding; S7, cutting the cured parts after demoulding to obtain the finished composite material skirt board.

2. A method for manufacturing a composite material skirt panel according to claim 1, characterized in that: The steps of laying an isolation film on the surface of the core mold to prepare a core mold preform, combining two core mold preforms, laying outer cladding sheets on the surfaces of both, and forming a combined preform include the following steps: S31, selecting two core molds of different shapes; S32, laying an isolation film on the surface of the core mold and attaching it tightly by vacuuming; S33, laying the inner cavity coating layer sheets on the surface of the core mold in sequence until the laying is completed to form an inner cavity coating layer laying group, and obtain a core mold preform; S34, filling yarn in the R angle triangle area based on the equal cross-section calculation of the two core mold preforms; S35, assembling and mounting the two core mold preforms on a rotating fixture, and laying the outer cladding sheets on the outer surfaces of the two core mold preforms in sequence by rotation until the laying is completed to form an outer cladding fiber ply group and obtain a combined preform.

3. A method for manufacturing a composite material skirt panel according to claim 2, characterized in that: The core mold includes a triangular paving core mold and a rectangular paving core mold, and the triangular paving core mold and the rectangular paving core mold are combined to form a skirt board structure.

4. The method for manufacturing a composite material skirt panel according to claim 2, characterized in that: The filling of yarn in the R angle triangle area based on the equal cross-section calculation of the two core mold preforms includes the following steps: S341, obtaining the R angle position formed between the two core mold preforms, obtaining the equal cross-section of the core mold preform, and measuring the shape parameters of the R angle triangle area; S342, converting density to volume according to known fiber density, calculating the filling amount in the R-angle triangle area, and then selecting filling materials to fill the corresponding positions.

5. A method for manufacturing a composite material skirt panel according to claim 4, characterized in that: During the laying process of the inner cavity coating layer laying group and the outer cladding fiber layer laying group, vacuum compaction is performed once every 2-6 layers until 9 layers are laid.

6. The method for manufacturing a composite material skirt panel according to claim 1, characterized in that: The step of placing the combined preform that has escaped from the core mold into the upper and lower molds and then laying the combined material comprises the following steps: S41, removing the core mold from the two core mold preforms; S42, placing the combined preform in the upper mold and the lower mold of the mold for mold closing, and placing a sealing strip between the upper mold and the lower mold to eliminate the mold closing gap; S43, lay the combined materials in the mold cavity in order, bag and seal them, and test the air tightness.

7. A method for manufacturing a composite material skirt panel according to claim 6, characterized in that: The combined materials include a release cloth, a porous isolation film, a breathable felt and a vacuum bag film, and the laying order is the release cloth, the porous isolation film, the breathable felt and the vacuum bag film.

8. The method for manufacturing a composite material skirt panel according to claim 1, characterized in that: The step of sealing the mold and then heating and curing it in a curing furnace comprises the following steps: S51, installing the side metal plate of the mold, sealing and fixing the mold, so that the air nozzle on the side metal plate and the vacuum bag film form a sealed cavity; S52, placing the mold into a curing furnace for heating and curing, and connecting the air nozzle on the metal plate on the side of the mold to control the curing pressure inside the mold by compressed air until the curing is completed.

9. A method for manufacturing a composite material skirt panel according to claim 8, characterized in that: The curing pressure is 0.3MPa-0.6Mpa.

10. The method for manufacturing a composite material skirt panel according to claim 1, characterized in that: The process of removing the cured part from the mold for demoulding comprises the following steps: S61, removing the side metal plate of the mold, and taking out the cured part by demoulding; S62, cooling the cured part to room temperature, removing the mold, and removing the auxiliary materials.

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