A hoisting partition wall for high-speed trains and its forming method

Abstract

This invention discloses a hoisting partition wall for high-speed trains and its molding method. The partition wall is used to connect to the underframe of a high-speed train and includes a hoisting partition wall body integrally molded from a carbon fiber sandwich composite material. The carbon fiber sandwich composite material comprises a carbon fiber skin, a film, and a foam core, forming a sandwich structure. The hoisting partition wall body is equipped with multiple connecting seats and tie rods. This hoisting partition wall for high-speed trains has the advantages of light weight, high strength, and high integrity.

Description

Technical Field

[0001] This invention relates to the field of new materials application technology for rail transit, specifically to a hoisting partition wall for high-speed trains and its forming method. Background Technology

[0002] Below the underframe of the EMU (Electric Multiple Unit) is an equipment compartment to house the undercarriage equipment. At both ends of the equipment compartment are suspended partitions, which are symmetrical along the longitudinal center of the car body, providing storage space and protection for the undercarriage equipment. In practical applications, the suspended partitions have certain requirements regarding strength, impact resistance, and flame retardancy.

[0003] In the existing EMU manufacturing process, the hoisting partition wall is formed by welding metal plates or metal profiles. Because this metal partition wall uses welding technology, it will result in large deformation, low flatness, large weight of metal materials, complicated installation, poor overall integrity, and insufficient safety. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide a lightweight, high-strength and high-integration hoisting partition wall for EMU trains and its forming method.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A hoisting partition wall for high-speed trains, used to connect to the underframe of the high-speed train, includes a hoisting partition wall body integrally formed using carbon fiber sandwich composite material. The carbon fiber sandwich composite material includes a carbon fiber skin, a film, and a foam core material, which constitute a sandwich structure.

[0007] As a further improvement to the above technical solution:

[0008] The carbon fiber skin is a carbon fiber flame-retardant prepreg, the foam core is a fiber-reinforced phenolic foam core, and the adhesive film is an epoxy adhesive film.

[0009] The foam core material has multiple embedded metal parts, which are arranged at various connection positions of the hoisted partition wall body. The upper and lower surfaces of the embedded metal parts are each covered with a layer of glass fiber flame-retardant prepreg to prevent electrochemical corrosion.

[0010] The hoisting partition wall body is provided with multiple connecting seats for connecting with the EMU. The connecting seats are detachably connected to the pre-embedded metal parts in the hoisting partition wall body through a connecting mechanism.

[0011] The connecting mechanism includes bolts, and bolt holes are correspondingly provided on the embedded metal part. The bolts pass through the connecting seat and are threadedly connected to the embedded metal part to press the connecting seat against the hoisting partition wall body.

[0012] A plurality of wire tying rods for fixing the EMU wire harness are connected to the hoisting partition wall body.

[0013] As a general inventive concept, on the other hand, the present invention provides a forming method for the above-mentioned hoisting partition wall for EMUs, including the following steps:

[0014] Step 1: Mold preparation: Put the mold into an oven at 60°C - 80°C and bake for 30 ± 5 minutes. Use a copper spatula to clean the residual resin residue adhered to the mold, clean the mold with a dust-free cloth soaked in industrial alcohol, ensure that the surface of the mold is clean, without impurities such as oil stains and dust. After the alcohol wipe dries, apply an appropriate amount of mold release agent to the surface of the mold with a dust-free cloth, ensure that the mold release agent is evenly applied. Wait for 5 minutes after the first application and then apply it a second time;

[0015] Step 2: Raw material cutting: Use a cutting machine to cut the 200g / ㎡ carbon fiber flame-retardant prepreg, 400g / ㎡ carbon fiber flame-retardant prepreg, 300g / ㎡ glass fiber flame-retardant prepreg, and 250g / ㎡ epoxy film according to the cutting diagram. Prepare the fiber-reinforced phenolic foam core material and the embedded metal part according to the required dimensions;

[0016] Step 3: Laying: Lay the outer skin, film, foam core material, embedded metal part, film, and inner skin in sequence. The outer skin and the inner skin are carbon fiber flame-retardant prepregs. Lay the 15mm, 13.5mm, and 9mm fiber-reinforced phenolic foam core materials according to the drawing partitions. Locate the embedded position of the embedded metal part according to the drawing and the epoxy board tooling. After marking on the core material, cut out a hole for the embedded metal part. When laying the embedded metal part, lay one layer of 300g / ㎡ glass fiber flame-retardant prepreg on each of the upper and lower surfaces, and then lay the auxiliary materials, that is, lay the release cloth, isolation film, and breather felt in sequence;

[0017] Step 4: Autoclave curing: Use a sealing strip to stick a circle around the mold, attach the vacuum bag and seal it and then pump it to vacuum and measure the pressure holding. After holding the pressure for 30s, the pressure reduction ≤ 0.1kpa is qualified. Then put the product into the autoclave. The curing conditions are: heat up to 80°C in half an hour at room temperature (25°C), then keep warm for 1 hour, then heat up to 140°C in half an hour and keep warm for 2.5 hours to end. During the curing process, pressurize the autoclave to 0.3MPa. After curing, cool down to below 60°C and release the pressure to take out the mold;

[0018] Step 5: CNC machining to ensure that the processing dimensions of the hoisting partition wall body meet the requirements of the drawing;

[0019] Step 6: CNC machining is used to drill holes at the locations of the pre-embedded metal parts, and the connecting seat and tie rod are installed on the suspended partition wall body.

[0020] As a further improvement to the above technical solution:

[0021] In step three, the layup design sequence is as follows:

[0022] Outer skin: Two layers of 200g / ㎡ carbon fiber flame-retardant prepreg and five layers of 400g / ㎡ carbon fiber flame-retardant prepreg are laid in sequence;

[0023] Adhesive film: Lay one layer of epoxy adhesive film;

[0024] Foam core material: 15mm, 13.5mm and 9mm fiber-reinforced phenolic foam are laid in sections. At the 13.5mm fiber-reinforced phenolic foam positions, one layer of 200g / ㎡ carbon fiber flame-retardant prepreg and three layers of 400g / ㎡ carbon fiber flame-retardant prepreg are laid in sequence. At the 9mm fiber-reinforced phenolic foam positions, one layer of 200g / ㎡ carbon fiber flame-retardant prepreg and thirteen layers of 400g / ㎡ carbon fiber flame-retardant prepreg are laid in sequence.

[0025] Adhesive film: Lay one layer of epoxy adhesive film;

[0026] Inner skin: Five layers of 400g / ㎡ carbon fiber flame-retardant prepreg and two layers of 200g / ㎡ carbon fiber flame-retardant prepreg are laid in sequence; the total product thickness is guaranteed to be consistent after curing in an autoclave.

[0027] The overall thickness of the hoisted partition wall body after curing in an autoclave is 20mm.

[0028] After being cured in an autoclave, the suspended partition wall body is machined by CNC machining to reduce the thickness of some 13.5mm fiber-reinforced phenolic foam sections to 4mm and the thickness of some 9mm fiber-reinforced phenolic foam sections to 14mm.

[0029] Compared with the prior art, the advantages of the present invention are as follows: The hoisting partition wall for EMUs of the present invention is made of carbon fiber sandwich composite material. The carbon fiber sandwich composite material has a sandwich structure, which has the characteristics of low specific gravity, good rigidity and high strength. Compared with metal partition walls, it reduces the weight by 35% to 40%, which can achieve high strength and lightweight hoisting partition wall. It can be convenient to install and improve safety. It has high impact resistance. Moreover, it adopts an integrated molding process. Compared with the welding process of metal partition walls, which leads to large deformation, low flatness and poor integrity, it will not produce processing deformation and has the advantages of high flatness, high integrity and high safety. Attached Figure Description

[0030] Figure 1 A three-dimensional structural diagram of a hoisting partition wall for high-speed trains.

[0031] Figure 2 This is a three-dimensional structural diagram of the hoisted partition wall.

[0032] Figure 3 This is a schematic diagram of the structure of carbon fiber sandwich composite material.

[0033] Legend:

[0034] 1. Carbon fiber sandwich composite material; 11. Carbon fiber skin; 111. Outer skin; 112. Inner skin; 12. Adhesive film; 13. Foam core material; 2. Suspended partition wall body; 3. Connecting seat; 4. Tie rod. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] like Figures 1 to 3 As shown, the hoisting partition wall for the EMU in this embodiment is used to connect to the underframe of the EMU. It includes a hoisting partition wall body 2 integrally formed by carbon fiber sandwich composite material 1. The carbon fiber sandwich composite material 1 includes carbon fiber skin 11, adhesive film 12 and foam core material 13. The carbon fiber skin 11, adhesive film 12 and foam core material 13 constitute a sandwich structure. The hoisting partition wall for high-speed trains of the present invention is made of carbon fiber sandwich composite material 1. The carbon fiber sandwich composite material 1 has a sandwich structure, that is, the center of the material is a foam core material 13, the opposite sides of the foam core material 13 are adhesive films 12, and the outer sides of the adhesive films 12 are carbon fiber skins 11. It has the characteristics of low specific gravity, good rigidity and high strength. Compared with metal partition walls, it reduces weight by 35% to 40%, which can achieve high strength and lightweight hoisting partition walls. It can be convenient to install and improve safety. It has high impact resistance. Moreover, it adopts an integrated molding process. Compared with the disadvantages of metal partition walls, which are caused by welding process, resulting in large deformation, low flatness and poor integrity, it will not produce processing deformation and has the advantages of high flatness, high integrity and high safety.

[0037] In this embodiment, the carbon fiber skin 11 is a carbon fiber flame-retardant prepreg, the foam core 13 is a fiber-reinforced phenolic foam core, and the adhesive film 12 is an epoxy adhesive film. The use of fiber-reinforced phenolic foam core further reduces weight, achieving lightweight suspended partitions while maintaining high rigidity, and also meeting the flame-retardant and environmentally friendly performance requirements of suspended partitions. The fiber-reinforced phenolic foam core is the core material mentioned in patent number CN201911030141.7, "A Phenolic Resin Foamed Prepreg, Its Preparation Method and Application".

[0038] In this embodiment, multiple embedded metal parts are pre-embedded within the foam core material 13. These pre-embedded metal parts are arranged at various connection positions of the hoisting partition body 2. A layer of fiberglass flame-retardant prepreg is laid on the upper and lower surfaces of each embedded metal part to prevent electrochemical corrosion. The connection positions of the hoisting partition body 2 refer to the locations where the integrally formed hoisting partition body 2 connects to other structures (train car bodies). Setting embedded metal parts at these connection positions enhances the strength of the stress points, ensuring the reliability and stability of the connection. Embedding the embedded metal parts within the foam core material 13 and integrally forming them together facilitates one-time molding, reducing manufacturing difficulty. Laying fiberglass flame-retardant prepreg on the upper and lower surfaces of the embedded metal parts prevents electrochemical corrosion and ensures the accuracy of the height and position of the embedded metal parts. Preferably, the outer contour and connection positions of the hoisting partition are designed according to the interface of the train car body, facilitating connection and installation, and ensuring the reliability of the hoisting partition during operation after installation on the car body.

[0039] In this embodiment, the hoisting partition wall body 2 is provided with multiple connecting seats 3 for connecting with the EMU (Electric Multiple Unit). The connecting seats 3 are detachably connected to the pre-embedded metal parts in the hoisting partition wall body 2 via a connecting mechanism. In this embodiment, the hoisting partition wall is connected to the C-shaped groove, curved beam column, and cross beam column on the car body through each connecting seat 3. The connecting seats 3 are connected to the pre-embedded metal parts through the connecting mechanism, which can fix the connecting seats 3 to the hoisting partition wall body 2. Then, the hoisting partition wall is connected to the EMU through the connecting seats 3. The connecting mechanism connects the connecting seats 3 and the hoisting partition wall body 2 in a detachable manner, which facilitates the adjustment of the connecting seats 3 and the EMU according to actual usage requirements during reinstallation, thus improving the flexibility of use.

[0040] In this embodiment, the connecting mechanism includes bolts. Bolt holes are correspondingly provided on the embedded metal parts. The bolts pass through the connecting seat 3 and are threadedly connected to the embedded metal parts, pressing the connecting seat 3 onto the suspended partition wall body 2. The bolt holes on the embedded metal parts can be machined using CNC machining. Similarly, the connecting holes on the corresponding embedded metal parts can be machined using CNC machining after the suspended partition wall body 2 is integrally formed. The connecting seat 3 is then connected to the suspended partition wall body 2 using bolts. This design is simple, provides a reliable and stable connection, and facilitates installation and disassembly.

[0041] In this embodiment, the main body 2 of the hoisting partition wall is connected with multiple cable ties 4 for fixing the EMU wiring harness. The cable ties 4 are riveted to the main body 2 of the hoisting partition wall, which can effectively fix the EMU wiring harness to the hoisting partition wall and ensure the cleanliness of the interior space of the hoisting partition wall.

[0042] The forming method of the hoisting partition wall for EMUs in this embodiment is applied to the hoisting partition wall for EMUs as described above, and includes the following steps:

[0043] Step 1: Mold preparation: Place the mold in an oven at 60°C - 80°C and bake for 30 ± 5 minutes. Use a copper spatula to clean the residual resin residue adhered to the mold. Clean the mold with a lint-free cloth soaked in industrial alcohol to ensure the mold surface is clean, free of impurities such as oil stains and dust. After the alcohol wipe dries, apply an appropriate amount of mold release agent to the mold surface with a lint-free cloth, ensuring even application. Wait 5 minutes after the first application and then apply a second coat;

[0044] Step 2: Raw material cutting: Use a cutting machine to cut 200g / ㎡ carbon fiber flame-retardant prepreg, 400g / ㎡ carbon fiber flame-retardant prepreg, 300g / ㎡ glass fiber flame-retardant prepreg, and 250g / ㎡ epoxy film according to the cutting diagram. Prepare the fiber-reinforced phenolic foam core material and embedded metal parts according to the required dimensions;

[0045] Step 3: Laying: Lay the outer skin 111, film 12, foam core material 13, embedded metal parts, film 12, and inner skin 112 in sequence. The outer skin 111 and inner skin 112 are carbon fiber flame-retardant prepregs. Lay 15mm, 13.5mm, and 9mm fiber-reinforced phenolic foam core materials according to the drawing partitions. Locate the embedding positions of the embedded metal parts according to the drawing and the epoxy board tooling. After scribing and positioning on the core material, cut holes for the embedded metal parts. When laying the embedded metal parts, lay one layer of 300g / ㎡ glass fiber flame-retardant prepreg on each of the upper and lower surfaces, and then lay auxiliary materials, that is, lay the release cloth, isolation film, and breather felt in sequence;

[0046] Step 4: Autoclave curing: Use a sealing strip to paste around the mold, attach the vacuum bag, seal it, and then evacuate and measure the pressure holding. After 30s of pressure holding, a pressure reduction ≤ 0.1kpa is qualified. Then place the product in the autoclave. The curing conditions are as follows: heat up from room temperature (25°C) to 80°C in half an hour, then keep warm for 1 hour, then heat up to 140°C in half an hour, and keep warm for 2.5 hours to end. During the curing process, pressurize the autoclave to 0.3MPa. After curing, cool down to below 60°C and release the pressure to remove the mold;

[0047] Step 5: CNC machining to ensure that the machining dimensions of the hoisting partition wall body 2 meet the requirements of the drawing;

[0048] Step 6: Drill holes at the positions of the embedded metal parts by CNC machining, and install the connecting seat 3 and the tie rod 4 on the hoisting partition wall body 2.

[0049] In Step 5 and Step 6, the accuracy of the hoisting partition wall can be ensured through the machining contour and interface holes.

[0050] In this embodiment, in Step 3, the laying design sequence is as follows:

[0051] Outer skin 111: Two layers of 200g / ㎡ carbon fiber flame-retardant prepreg and five layers of 400g / ㎡ carbon fiber flame-retardant prepreg are laid in sequence;

[0052] Epoxy film 12: Lay one layer of epoxy film;

[0053] Foam core material 13: 15mm, 13.5mm and 9mm fiber-reinforced phenolic foam are laid in sections. At the 13.5mm fiber-reinforced phenolic foam positions, one layer of 200g / ㎡ carbon fiber flame-retardant prepreg and three layers of 400g / ㎡ carbon fiber flame-retardant prepreg are laid in sequence. At the 9mm fiber-reinforced phenolic foam positions, one layer of 200g / ㎡ carbon fiber flame-retardant prepreg and thirteen layers of 400g / ㎡ carbon fiber flame-retardant prepreg are laid in sequence.

[0054] Epoxy film 12: Lay one layer of epoxy film;

[0055] Inner skin 112: Five layers of 400g / ㎡ carbon fiber flame-retardant prepreg and two layers of 200g / ㎡ carbon fiber flame-retardant prepreg are laid in sequence; the total product thickness is guaranteed to be consistent after curing in an autoclave.

[0056] In this embodiment, the overall thickness of the hoisted partition wall body 2 after curing in an autoclave is 20mm.

[0057] In this embodiment, the hoisting partition body 2 is cured in an autoclave and then machined using CNC machining. Based on the product drawings, the thickness of some 13.5mm fiber-reinforced phenolic foam sections is machined to 4mm, and the thickness of some 9mm fiber-reinforced phenolic foam sections is machined to 14mm. This design, where the hoisting partition is machined after being laid out in sections and prepreg is integrally formed, ensures that the dimensions of the hoisting partition match the installation dimensions of the equipment compartment vehicle after machining. It also ensures that the fiber-reinforced phenolic foam core material is not exposed after machining, improving the accuracy and reliability of product installation.

[0058] The above description is merely a preferred embodiment of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. For those skilled in the art, improvements and modifications obtained without departing from the inventive concept should also be considered within the scope of protection of the present invention.

Claims

1. A method for forming a hoisting partition wall for a high-speed train, applied to a hoisting partition wall for a high-speed train, the hoisting partition wall being connected to the underframe of the high-speed train, comprising a hoisting partition wall body (2) integrally formed from a carbon fiber sandwich composite material (1), the carbon fiber sandwich composite material (1) comprising a carbon fiber skin (11), an adhesive film (12), and a foam core material (13), the carbon fiber skin (11), the adhesive film (12), and the foam core material (13) constituting a sandwich structure, characterized in that: It includes the following steps: Step 1: Mold preparation: Place the mold in an oven at 60°C - 80°C and bake for 30 ± 5 minutes. Use a copper spatula to clean the residual resin residues adhered to the mold. Clean the mold with a lint-free cloth soaked in industrial alcohol to ensure the mold surface is clean and free of impurities. After the alcohol is wiped dry, apply an appropriate amount of mold release agent to the mold surface with a lint-free cloth, ensuring uniform application. Wait for 5 minutes after the first application and then apply it a second time; Step 2: Raw material cutting: Use a cutting machine to cut 200g / ㎡ carbon fiber flame-retardant prepreg, 400g / ㎡ carbon fiber flame-retardant prepreg, 300g / ㎡ fiberglass flame-retardant prepreg, and 250g / ㎡ epoxy film according to the cutting diagram. Prepare the fiber-reinforced phenolic foam core material and embedded metal parts according to the required dimensions; Step 3: Laying: Lay the outer skin (111), film (12), foam core material (13), embedded metal parts, film (12), and inner skin (112) in sequence. The outer skin (111) and inner skin (112) are carbon fiber flame-retardant prepregs. Lay 15mm, 13.5mm, and 9mm fiber-reinforced phenolic foam core materials according to the drawing partitions. Locate the embedded position of the embedded metal parts according to the drawing and the epoxy board tooling. After marking on the core material, cut out holes of the size of the embedded metal parts. When laying the embedded metal parts, lay one layer of 300g / ㎡ fiberglass flame-retardant prepreg on each of the upper and lower surfaces, and then lay auxiliary materials, that is, lay the release cloth, isolation film, and breather felt in sequence; Step 4: Autoclave curing: Use a sealing strip to stick around the mold, attach the vacuum bag, seal the bag, and then evacuate and measure the pressure holding. After holding the pressure for 30s, if the pressure reduction is ≤ 0.1kpa, it is qualified. Then place the product in the autoclave. The curing conditions are: heat up to 80°C in half an hour at room temperature (25°C), then keep warm for 1 hour, then heat up to 140°C in half an hour, and keep warm for 2.5 hours to end. During the curing process, pressurize the autoclave to 0.3MPa. After curing, cool down to below 60°C and relieve the pressure to take out the mold; Step 5: CNC machining to ensure that the processing dimensions of the hoisting partition wall body (2) meet the requirements of the drawing; Step 6: CNC machining to drill holes at the position of the embedded metal parts, and install the connecting seat (3) and the tying rod (4) on the hoisting partition wall body (2); In Step 3, the laying design sequence is as follows: Outer skin (111): Lay 2 layers of 200g / ㎡ carbon fiber flame-retardant prepreg and 5 layers of 400g / ㎡ carbon fiber flame-retardant prepreg in sequence; Film (12): Lay 1 layer of epoxy film; Foam core material (13): Partitionally lay 15mm, 13.5mm, and 9mm fiber-reinforced phenolic foam. At the position of 13.5mm fiber-reinforced phenolic foam, lay 1 layer of 200g / ㎡ carbon fiber flame-retardant prepreg and 3 layers of 400g / ㎡ carbon fiber flame-retardant prepreg in sequence. At the position of 9mm fiber-reinforced phenolic foam, lay 1 layer of 200g / ㎡ carbon fiber flame-retardant prepreg and 13 layers of 400g / ㎡ carbon fiber flame-retardant prepreg in sequence; Film (12): Lay 1 layer of epoxy film; Inner skin (112): Five layers of 400g / ㎡ carbon fiber flame retardant prepreg and two layers of 200g / ㎡ carbon fiber flame retardant prepreg are laid in sequence; the total product thickness is guaranteed to be consistent after curing in a hot autoclave.

2. The molding method of the hoisting partition wall for EMU according to claim 1, wherein the overall thickness of the hoisting partition wall body (2) after curing in a hot autoclave is 20mm.

3. The forming method of the hoisting partition wall for EMUs according to claim 2, characterized in that: The hoisting partition body (2) is cured in a hot autoclave and then machined by CNC machine to reduce the thickness of some 13.5mm fiber-reinforced phenolic foam positions to 4mm and the thickness of some 9mm fiber-reinforced phenolic foam positions to 14mm.

4. The forming method of the hoisting partition wall for EMU trains according to claim 1, characterized in that: The carbon fiber skin (11) is a carbon fiber flame-retardant prepreg, the foam core material (13) is a fiber-reinforced phenolic foam core material, and the adhesive film (12) is an epoxy adhesive film.

5. The forming method of the hoisting partition wall for high-speed trains according to claim 1, characterized in that: The foam core material (13) has multiple embedded metal parts, which are arranged at the connection positions of the hoisting partition wall body (2). The upper and lower surfaces of the embedded metal parts are each covered with a layer of glass fiber flame-retardant prepreg to prevent electrochemical corrosion.

6. The forming method of the hoisting partition wall for high-speed trains according to claim 5, characterized in that: The hoisting partition wall body (2) is provided with multiple connecting seats (3) for connecting with the EMU. The connecting seats (3) are detachably connected to the pre-embedded metal parts in the hoisting partition wall body (2) through the connecting mechanism.

7. The forming method of the hoisting partition wall for EMUs according to claim 6, characterized in that: The connecting mechanism includes bolts, and the embedded metal part is provided with corresponding bolt holes. The bolts pass through the connecting seat (3) and are threadedly connected to the embedded metal part to press the connecting seat (3) onto the hoisting partition body (2).

8. The method for forming the hoisting partition wall for EMUs according to any one of claims 1 to 7, characterized in that: The hoisting partition wall body (2) is connected to multiple tie rods (4) for fixing the EMU wiring harness.

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