Coated bottom plate of bogie and forming method of coated bottom plate

Abstract

The bogie wrapping bottom plate is formed by splicing a plurality of bottom plates, each bottom plate is in butt joint with a corresponding interface of the bogie, and a detection door is installed on the bottom plate corresponding to the position of a wheel set. The bogie wrapping bottom plate is characterized in that the bottom plate comprises a framework and an anti-impact skin covering the framework, and the anti-impact skin is formed by aramid fiber prepreg; the detection door comprises a framework and a high-temperature-resistant skin covering the framework, and the high-temperature-resistant skin is formed by prepreg made of bismaleimide resin and aramid fibers. The probability that the wrapping bottom plate is impacted and punctured by foreign matter when the bullet train moves at a high speed is effectively reduced, the reliability of shielding protection and airflow guiding of the wrapping bottom plate to the bottom of the bogie is improved, the detection door has good impact resistance and excellent high-temperature resistance, high-temperature radiation can be effectively resisted, the probability of deformation or damage is reduced, and the service life of the bullet train is prolonged. Therefore, the working condition adaptability of the cladding bottom plate is improved, and the service life is prolonged. The invention further provides a forming method of the bogie wrapping bottom plate.

Description

Technical Field

[0001] The present invention relates to a bogie covering bottom plate, belonging to the field of bogie covering structures. Background Art

[0002] Most traditional bogie areas are of partial covering structures, mostly made of aluminum profiles welded together, mainly used for protecting the equipment under the vehicle and achieving an aesthetic effect. There is no bottom covering structure, and the drag reduction effect is negligible. However, high-speed bullet trains run at high speeds. If there is no shielding at the bottom of the bogie, the air flow will directly enter the bogie from the bottom when the train runs at high speed. Foreign objects such as sand and particulate matter on the ground are easily carried by the air flow into the interior of the bogie, hitting components such as pipelines and wires of the bogie, causing pits on the surface of the components, thereby affecting their strength and shortening their service life. Moreover, when the air flow passes through the bogie area, it is subject to a large aerodynamic resistance, which will reduce the aerodynamic performance of the bogie area and affect the vehicle operation energy consumption. In the existing system, in order to protect the bogie structure and reduce the running resistance of the EMU, a covering structure is provided at the bottom of the bogie to shield the entire bottom of the bogie, so that when the air flow passes through the bottom of the bogie, it cannot enter the interior of the bogie and is directly guided to the outside of the vehicle body through the covering bottom plate to prevent foreign objects from entering and reduce the air resistance. However, the existing bogie covering bottom plates have the following defects: 1. The covering bottom plate made of metal material has a large weight, increasing the vehicle's overall weight, which does not meet the lightweight requirement of the vehicle's overall weight. Although the covering bottom plate made of composite material is light in weight, its quality is affected by the material and forming process, resulting in poor integrity and limited impact resistance of the covering bottom. It is easy to be penetrated when encountering foreign object impact during the high-speed running of the bullet train, and the reliability is not high.

[0003] 2. The wheel sets of the bogie need to protrude from the covering bottom plate. When the bullet train brakes emergently, the wheel sets on the bogie will generate high temperature, and the temperature of the heat radiation received by the covering bottom plate is very high. The position where the wheel sets protrude is prone to deformation or damage due to temperature rise, affecting the effect of shielding and guiding the air flow at the bottom of the bogie, and also shortening the service life of the covering bottom plate. Summary of the Invention

[0004] The bogie covering bottom plate and its forming method provided by the present invention can effectively reduce the probability of the covering bottom plate being penetrated by foreign object impact during the high-speed running of the bullet train, improve the reliability of the covering bottom plate for shielding and protecting the bottom of the bogie and guiding the air flow. The inspection door not only has good impact resistance but also has excellent high-temperature resistance characteristics, can effectively resist the high-temperature radiation of the wheel sets, reduce the probability of deformation or damage of the inspection door, thereby improving the working condition adaptability of the covering bottom plate and extending its service life.

[0005] To achieve the above object, the technical solution adopted by the present invention is: The bogie covering bottom plate is formed by splicing multiple bottom plates. Each bottom plate is respectively butted with the corresponding interface of the bogie. A detection door is installed on the bottom plate corresponding to the wheel set position. A through hole for the wheel set to pass through is opened on the detection door. It is characterized in that: the bottom plate consists of a skeleton and an impact-resistant skin covering the skeleton. The impact-resistant skin is formed by an aramid fiber prepreg. The detection door includes a skeleton and a high-temperature-resistant skin covering the skeleton. The high-temperature-resistant skin is formed by a prepreg made of bismaleimide resin and aramid fiber.

[0006] Preferably, the skeleton is formed by welding aluminum profiles, and stainless steel guy ropes are riveted at the welding joints of adjacent aluminum profiles.

[0007] The forming method of the above-mentioned bogie covering bottom plate includes the following steps: First, make the corresponding skeletons according to the shapes and sizes of the bottom plate and the detection door respectively; Then, use the prepreg molding process to make the skins, and respectively obtain the impact-resistant skin and the high-temperature-resistant skin; Next, bond the impact-resistant skin to the skeleton with an adhesive and nail the impact-resistant skin and the skeleton tightly with rivets to form the bottom plate. Bond the high-temperature-resistant skin to the skeleton with an adhesive and nail the high-temperature-resistant skin and the skeleton tightly with rivets to form the detection door; After that, one end of the detection door is connected to the corresponding bottom plate at the wheel set position with a hinge, and the other end of the detection door is connected to the corresponding bottom plate at the wheel set position with bolts, and install the detection door on the corresponding bottom plate at the wheel set position; Finally, butt the bottom plates with the interfaces of the bogie respectively, and the bottom plates are spliced at the bottom of the bogie to form the bogie covering bottom plate.

[0008] Preferably, the specific steps of using the prepreg molding process to make the skin are: Step 1: Determine the required amount of prepreg according to the thickness of the impact-resistant skin or the high-temperature-resistant skin; Step 2: Prepare a clean mold, and cut out the prepreg with the corresponding shape and size according to the shape and size of the bottom plate or the detection door; Step 3: Obtain the skin by the method of laying and curing the prepreg in stages; Step 4: Carry out machining on the skin to obtain the finished skin product.

[0009] Preferably, the specific process of "obtaining the skin by the method of laying and curing the prepreg in stages" is: Primary lay-up and curing: First, lay the prepreg in the mold. The number of laying layers is half of the determined required amount of prepreg. Then, successively lay the release cloth, isolation film, and breather felt on the prepreg and cure it. Take out the mold to obtain the primary cured product; Secondary layup curing: After cleaning the surface flatness of the primary cured product, place it in a mold, then lay the remaining prepreg on the primary cured product. After laying the release cloth, isolation film, and breather felt on the prepreg, cure it and remove it from the mold to obtain the skin.

[0010] Preferably, before the primary layup, lay strip-shaped release cloth in the mold so that the strip-shaped release cloth is sandwiched between the bottom prepreg and the inner wall of the mold.

[0011] Preferably, before the primary layup, punch holes in each prepreg, and the punching positions correspond to the opening positions during the machining of the skin.

[0012] Preferably, the specific curing process is as follows: First, seal the mold with a sealing strip, stick on the vacuum bag, seal the bag, then evacuate and measure the pressure holding. After holding the pressure for 30 s, if the pressure reduction is ≤0.1 kPa, it is qualified; otherwise, it is unqualified and the mold needs to be resealed. Then, the mold enters the oven for curing. The curing conditions are: heat up to 80 °C at room temperature for half an hour and keep warm for 1 hour, then heat up to 140 °C for half an hour and keep warm for 2.5 hours. After curing, cool down to below 60 °C and remove it from the mold.

[0013] The beneficial effects of the invention are: The bogie covering bottom plate of the present invention, the bottom plate includes a skeleton and an impact-resistant skin. The impact-resistant skin is formed from aramid fiber prepreg. Utilize the superior impact resistance characteristics of aramid fiber, and combine the impact-resistant skin with the skeleton to ensure the strength and stiffness of the covering bottom plate, effectively reducing the probability of the covering bottom plate being penetrated by foreign objects during the high-speed movement of the EMU, improving the reliability of the covering bottom plate for shielding and guiding the airflow at the bottom of the bogie, and improving the reliability of the covering bottom plate on the basis of meeting the lightweight requirements of the whole vehicle; install a detection door on the bottom plate corresponding to the wheel set position. The high-temperature-resistant skin in the detection door is formed from prepreg made of bismaleimide resin and aramid fiber. Utilize the superior heat resistance characteristics of bismaleimide resin, so that the detection door not only has good impact resistance but also has superior high-temperature resistance, enabling the detection door to effectively resist the high-temperature radiation of the wheel set, reducing the probability of deformation or damage of the detection door, thereby improving the working condition adaptability of the covering bottom plate and extending its service life. Moreover, by setting a detection door at the wheel set position, the position with the most severe working conditions in the covering bottom plate is at the detection door position. Utilize the convenient replacement feature of the detection door to replace it in a timely manner according to requirements to ensure the integrity of the covering bottom plate, thereby ensuring the effect of shielding and guiding the airflow at the bottom of the bogie.

[0014] During the formation of the skin, first lay and cure half of the aramid fiber prepreg, then lay the other half of the prepreg on the once-cured product and cure it again. By laying the layers in stages and curing each time, the bonding force between layers is enhanced layer by layer, the internal stress during final curing is reduced, thereby reducing the risk of delamination. Multiple curing can make each layer bond more tightly during curing, avoiding stress concentration generated during one-time curing, strengthening the interlayer bonding force, reducing delamination, improving the forming process of the skin, and improving the curing quality, thus improving the overall performance of the skin and the skin quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 FIG. is a schematic diagram of the bogie covering bottom plate of the present invention.

[0016] Figure 2 FIG. is a schematic diagram of the bottom plate formed by combining the skeleton and the impact-resistant skin.

[0017] Figure 3 FIG. is a schematic diagram of installing a detection door on the bottom plate corresponding to the wheel set position. DETAILED DESCRIPTION OF THE INVENTION

[0018] The following Figures 1 to 3 will describe the embodiments of the present invention in detail.

[0019] The bogie covering bottom plate is formed by splicing a plurality of bottom plates 1. Each bottom plate 1 is respectively butted with the corresponding interface of the bogie. A detection door 4 is installed on the bottom plate 1 corresponding to the wheel set position. A through hole for the wheel set to pass through is opened on the detection door 4. It is characterized in that: the bottom plate 1 includes a skeleton 2 and an impact-resistant skin 3 covering the skeleton 2. The impact-resistant skin 3 is formed by aramid fiber prepreg. The detection door 4 includes a skeleton 2 and a high-temperature-resistant skin 5 covering the skeleton 2. The high-temperature-resistant skin 4 is formed by a prepreg made of bismaleimide resin and aramid fiber.

[0020] The bogie covering bottom plate described above, the bottom plate 1 includes a skeleton 2 and an impact-resistant skin 3. The impact-resistant skin 3 is formed by aramid fiber prepreg. By utilizing the superior impact resistance characteristics of aramid fiber and combining the impact-resistant skin 3 with the skeleton 2, the strength and stiffness of the covering bottom plate are ensured, effectively reducing the probability of the covering bottom plate being penetrated by foreign objects during the high-speed movement of the EMU, improving the reliability of the covering bottom plate for shielding and protecting the bottom of the bogie and guiding the air flow, and improving the reliability of the covering bottom plate on the basis of meeting the lightweight requirements of the whole vehicle; a detection door 4 is installed on the bottom plate 1 corresponding to the wheel set position. The high-temperature-resistant skin 5 in the detection door 4 is formed by prepreg made of bismaleimide resin and aramid fiber. By utilizing the superior temperature resistance characteristics of bismaleimide resin, the detection door 4 not only has good impact resistance but also has superior high-temperature resistance characteristics, enabling the detection door 4 to effectively resist the high-temperature radiation of the wheel set, reducing the probability of deformation or damage of the detection door 4, thereby improving the working condition adaptability of the covering bottom plate and extending its service life. Moreover, by setting the detection door 4 at the wheel set position, the position with the most severe working conditions in the covering bottom plate is at the detection door position. By taking advantage of the convenient replacement of the detection door, it can be replaced in a timely manner according to requirements to ensure the integrity of the covering bottom plate, thereby ensuring the effect of shielding and guiding the air flow at the bottom of the bogie.

[0021] Among them, the skeleton 2 is formed by welding aluminum profiles, and stainless steel guy ropes are riveted at the welding joints of adjacent aluminum profiles. Connecting adjacent aluminum profiles with stainless steel guy ropes ensures that the skeleton 2 can still maintain an integral structure after the welding failure of adjacent aluminum profiles, improving the structural stability of the bottom plate and extending its service life.

[0022] The present invention also protects a forming method of the above-mentioned bogie covering bottom plate, including the following steps: First, corresponding skeletons 2 are respectively manufactured according to the shapes and sizes of the bottom plate 1 and the detection door 4; Then, the skins are manufactured by the prepreg molding process to respectively obtain the impact-resistant skin 3 and the high-temperature-resistant skin 5; Next, the impact-resistant skin 3 is bonded to the skeleton 3 with an adhesive and the impact-resistant skin 3 and the skeleton 2 are nailed tightly with rivets to form the bottom plate 1, and the high-temperature-resistant skin 5 is bonded to the skeleton 2 with an adhesive and the temperature-resistant skin and the skeleton are nailed tightly with rivets to form the detection door 4; After that, one end of the detection door 4 is connected to the bottom plate 1 corresponding to the wheel set position with a hinge, and the other end of the detection door 4 is connected to the bottom plate 1 corresponding to the wheel set position with bolts, and the detection door 4 is installed on the bottom plate 1 corresponding to the wheel set position; Finally, the bottom plate 1 is respectively docked with the interfaces of the bogie, and each bottom plate 1 is assembled at the bottom of the bogie to form the bogie covering bottom plate.

[0023] For the above-mentioned forming method, first, the frameworks 2 corresponding to the bottom plate 1 and the inspection door 4 are fabricated respectively, and then the corresponding skins are made with the corresponding prepregs to obtain the impact-resistant skin 3 and the high-temperature-resistant skin 5. After that, the skins and the frameworks are fixed by adhesives and rivets through double connection to ensure the connection stability between the skin and the framework during the high-speed operation of the EMU. After the bottom plate 1 and the inspection door 4 are manufactured, the inspection door is installed on the bottom plate 1. Finally, the bottom plate 1 is docked with the interface on the bogie, thus completing the assembly of each bottom plate on the bogie to form the coated bottom plate. The forming process is simple and easy to operate, ensuring the integrity of the coated bottom plate.

[0024] Among them, the specific steps for manufacturing the skin by using the prepreg forming process are as follows: Step 1: Determine the quantity of prepreg required according to the thickness of the impact-resistant skin or the high-temperature-resistant skin. Step 2: Prepare a clean mold, and cut out the prepreg with the corresponding shape and size according to the shape and size of the bottom plate or the inspection door. Step 3: The prepreg is laminated and cured in stages to obtain the skin. Step 4: Perform machining on the skin to obtain the finished skin product.

[0025] The prepreg is laminated and cured in stages. By laminating and curing in stages, the interfacial bonding strength is enhanced, delamination is reduced, and at the same time, the discharge of air and volatiles is promoted, the porosity is reduced, the defect that the resin impregnation of the aramid fiber prepreg is poor and it is easy to cause delamination of the product is overcome, the forming process of the skin is improved, the curing quality is enhanced, thereby improving the overall performance of the skin and the quality of the skin.

[0026] Among them, the specific process of "the prepreg is laminated and cured in stages to obtain the skin" is as follows: Primary lamination and curing: First, lay the prepreg in the mold, and the number of layers laid is half of the determined required quantity of prepreg. Then, successively lay the release cloth, the isolation film, and the breather felt on the prepreg and cure it. After demolding, obtain the primary cured product. Secondary lamination and curing: After cleaning the surface flatness of the primary cured product, place it in the mold, then lay the remaining prepreg on the primary cured product, lay the release cloth, the isolation film, and the breather felt on the prepreg and cure it. After demolding, obtain the skin.

[0027] During the formation of the skin, first lay and cure half of the aramid fiber prepreg, then lay the other half of the prepreg on the once-cured finished product and cure it again. By laying the layers in stages and curing each layer during laying, the bonding force between layers is enhanced layer by layer, the internal stress during final curing is reduced, thereby reducing the risk of delamination. Multiple curing allows each layer to bond more tightly during curing, avoiding stress concentration generated during one-time curing, strengthening the interlayer bonding force, reducing delamination, improving the forming process of the skin, and improving the curing quality, thereby improving the overall performance of the skin and the skin quality.

[0028] Among them, before the first layup, lay strip-shaped release cloth in the mold so that the strip-shaped release cloth is sandwiched between the bottom prepreg and the inner wall of the mold. By laying the strip-shaped release cloth, a gap is formed between the mold and the prepreg, increasing the air circulation gap and reducing the formation of bubbles and pores, thereby further reducing delamination.

[0029] Among them, before the first layup, punch holes in each prepreg, and the punching positions correspond to the opening positions during the machining of the skin. Punching holes at the corresponding positions on the prepreg can avoid the openings after the machining of the skin. Only the holes need to be trimmed during machining, reducing the damage to the skin by the processing machine. Punching holes in the prepreg can increase the exhaust channels during the curing process, reduce the porosity, further reduce delamination, and improve the curing quality.

[0030] Among them, the specific curing process is as follows: First, seal the mold with a sealing strip, stick the vacuum bag, seal the bag, then evacuate and measure the pressure holding. After holding the pressure for 30s, if the pressure reduction ≤ 0.1kpa, it is qualified; otherwise, it is unqualified and the mold needs to be resealed. Then, the mold enters the oven for curing. The curing conditions are: heat up to 80°C at room temperature for half an hour and keep warm for 1 hour, then heat up to 140°C for half an hour and keep warm for 2.5 hours. After curing, cool down to below 60°C and take out the mold.

[0031] Adopt the above curing process to ensure the curing effect of the prepreg during the first curing and the second curing, thereby ensuring the skin quality.

[0032] The above combines the drawings to completely describe the technical solutions of the embodiments of the present invention. It should be noted that the described embodiments are only a part of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

Claims

1. The bogie covering bottom plate is composed of multiple bottom plates, each of which is connected to the corresponding interface of the bogie. A detection door is installed on the bottom plate corresponding to the position of the wheelset, and a through hole is provided on the detection door for the wheelset to pass through, which is characterized by: The bottom plate comprises a frame and an impact-resistant skin covering the frame, the impact-resistant skin is formed by aramid fiber prepreg, and the inspection door comprises a frame and a high-temperature resistant skin covering the frame, the high-temperature resistant skin is formed by prepreg made of bismaleimide resin and aramid fiber.

2. The bogie cladding bottom plate according to claim 1, characterized in that: The frame is formed by welding aluminum profiles, and stainless steel draw cords are riveted at the welding points of adjacent aluminum profiles.

3. The method for forming the bogie clad bottom plate according to claim 1 or 2, comprising the following steps: First, make corresponding frames according to the shapes and sizes of the base plate and the detection door; Then, the skin is manufactured by using a prepreg molding process, and an impact-resistant skin and a high-temperature-resistant skin are manufactured respectively; Next, the impact-resistant skin is bonded to the frame with an adhesive and the impact-resistant skin and the frame are fastened with rivets to form a bottom plate, and the high-temperature-resistant skin is bonded to the frame with an adhesive and the high-temperature-resistant skin and the frame are fastened with rivets to form a detection door; Afterwards, one end of the detection door is connected to the bottom plate corresponding to the wheelset position by a hinge, and the other end of the detection door is connected to the bottom plate corresponding to the wheelset position by bolts, and the detection door is installed on the bottom plate corresponding to the wheelset position; Finally, the bottom plates are connected to the interfaces of the bogies respectively, and the bottom plates are assembled at the bottom of the bogies to form the bogie covering bottom plates.

4. The method for forming a bogie clad bottom plate according to claim 3, characterized in that: The specific steps of making the skin using the prepreg molding process are: Step 1: Determine the amount of prepreg required according to the thickness of the impact-resistant skin or the high-temperature-resistant skin; Step 2: Prepare a clean mold and cut out prepreg of corresponding shape and size according to the shape and size of the base plate or inspection door; Step 3: The prepreg is laid up in stages and cured to obtain the skin; Step 4: Perform skinning machine processing to obtain the finished skinning product.

5. The method for forming a bogie cladding bottom plate according to claim 4, characterized in that: The specific process of "prepreg is laid up and cured in stages to make the skin" is: One-time layer curing: first lay the prepreg in the mold, the number of layers is half of the required number of prepreg, then put the demoulding cloth, isolation film, breathable felt on the prepreg in turn for post-curing, and remove the mold to obtain a one-time cured product; Secondary ply curing: After cleaning the surface of the first-cured product, place it in the mold and then lay the remaining prepreg on the first-cured product. Place a release cloth, isolation film, and breathable felt on the prepreg, then cure it and remove it from the mold to obtain the skin.

6. The method for forming a bogie cladding bottom plate according to claim 5, characterized in that: Before the primary layering, a strip of release cloth is laid in the mold so that the strip of release cloth is sandwiched between the bottom layer prepreg and the inner wall of the mold.

7. The method for forming a bogie cladding bottom plate according to claim 5, characterized in that: Each prepreg is punched before the first layer is laid, and the punching position corresponds to the hole opening position during skinning machine processing.

8. The method for forming a bogie cladding bottom plate according to claim 5, characterized in that: The specific process of curing is: First, seal the mold with a sealing strip, attach a vacuum bag, seal the bag, and then evacuate and measure the pressure. If the pressure drops ≤0.1kpa after 30s, it is qualified. Otherwise, it is unqualified and the mold needs to be re-sealed. Then, the mold enters the oven for curing. The curing conditions are to heat up to 80°C for half an hour at room temperature and keep it warm for 1 hour, then heat up to 140°C for another half an hour and keep it warm for 2.5 hours. After the curing is completed, the temperature is lowered to below 60°C and the mold is removed.

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