Anti-collision structure and preparation method thereof

Abstract

This application discloses an anti-collision structure and its preparation method. The anti-collision structure includes an inner support, a buffer layer, and a paint layer. The buffer layer is disposed on the outer surface of the inner support, and the paint layer is disposed on the outer surface of the buffer layer. The buffer layer contains a mesh and multiple layers of carbon fiber balls. This application can improve the buffering capacity of the anti-collision structure and increase its service life.

Description

Technical Field

[0001] This application relates to the field of anti-collision structures, and in particular to anti-collision structures and their preparation methods. Background Technology

[0002] Collisions frequently occur during vehicle movement. Minor collisions often cause paint to peel off, while major collisions often cause the anti-collision structure to break. How to improve the anti-fracture capability of the anti-collision structure and extend its service life has always been a problem. Summary of the Invention

[0003] To address the problems existing in the prior art, this application discloses an anti-collision structure, which includes an inner support body, a buffer layer, and a paint layer. The buffer layer is disposed on the outer surface of the inner support body, and the paint layer is disposed on the outer surface of the buffer layer.

[0004] The buffer layer contains a mesh and multiple layers of carbon fiber balls.

[0005] An adhesive is provided between the carbon fiber spheres in the buffer layer. The buffer layer contains at least four layers of carbon fiber spheres. An auxiliary mesh is disposed between the carbon fiber spheres in the buffer layer, with carbon fiber spheres on both the upper and lower sides of the mesh. The number of carbon fiber sphere layers on both sides of the auxiliary mesh is the same. Carbon fiber is mainly composed of carbon elements and can be made from acrylic fiber and viscose fiber through high-temperature oxidation and carbonization. It possesses high-temperature resistance, friction resistance, thermal conductivity, and corrosion resistance. Carbon fiber is fibrous and flexible. Due to its graphite microcrystalline structure preferentially oriented along the fiber axis, it has high strength and modulus along the fiber axis. In addition, carbon fiber also includes multi-walled carbon nanotubes. Experiments have shown that multi-walled carbon nanotubes have better spheroidization performance during spray granulation. The diameter of the carbon fiber is 100nm-10µm, and the diameter of the carbon fiber spheres is 5-50µm, which can be adjusted according to the solution concentration (the content of carbon fiber in the solution) and the nozzle size of the spray gun during the spray granulation process. The diameter of the carbon fiber balls; due to their porous structure and high toughness, the carbon fiber balls can buffer impact stress when a minor impact occurs; when the impact force increases, they can break the paint layer or cause the carbon fiber balls to shift, further buffering the impact stress through the shift of the carbon fiber balls; as long as the inner support is not broken, the surface scratches caused by the breakage can be repaired by spraying a carbon fiber ball solution containing adhesive and drying it, thus making repair convenient and effectively increasing the service life of the anti-collision structure; compared with some existing technologies that use foam to set the outside of the anti-collision structure, the chemical stability of foam is much lower than that of carbon fiber, and therefore the service life of the anti-collision structure of this application is not as long as that of the anti-collision structure; in addition, compared with setting the buffer layer as a solid fiber layer, since the fiber layer cannot form the effect of carbon fiber ball displacement, the fiber layer is prone to stress concentration at the most severely impacted position during the impact, which can easily cause the support below (or behind) the buffer layer to break.

[0006] The method for preparing the anti-collision structure includes the following steps:

[0007] Step P1: Prepare carbon fiber spheres;

[0008] Step P2: Place carbon fiber spheres on the surface of the inner support.

[0009] Step P3: Apply a coating to the surface of the carbon fiber ball.

[0010] Step P1 includes the following steps:

[0011] Step F1: Mixing. Place the carbon fiber and aqueous solution in a mixing container and ultrasonically stir until homogeneous.

[0012] Step F2: Spray granulation. The liquid in the mixed solution is spray-dried using a spray drying device to obtain the first carbon fiber ball. The spray drying process is as follows: the spray drying device adsorbs the mixed solution through a pipe to a high-temperature nozzle. The high-temperature nozzle has many tiny nozzles. The mixed solution in the high-temperature nozzle is sprayed out through the tiny nozzles under high pressure to form water droplets. The water droplets contain carbon fibers. An air supply device is installed outside the high-temperature nozzle. After passing through the air supply device and high-temperature and high-pressure spraying, the water in the water droplets is rapidly evaporated, and at the same time, the carbon fibers in the atomized droplets agglomerate into carbon fiber balls.

[0013] Step P2 includes the following process:

[0014] Step S1: Laying the attached mesh on the metal platform;

[0015] Step S2: Coating and drying. The solution containing the carbon fiber balls and adhesive is sprayed onto the upper surface of the attachment mesh through a coating gun and then dried. After the drying process, the solvent in the solution is evaporated, resulting in a carbon fiber ball and adhesive coating adhering to the upper surface of the attachment mesh.

[0016] Step S3: Separate by shovel, separating the attached mesh from the metal platform;

[0017] Step S4: Lay the metal platform on the reverse side. Flip the attached mesh with the coating on the upper surface and lay it on the metal platform. At this time, the reverse side of the attached mesh is facing up, and the coating on the lower surface of the attached mesh is in contact with the metal platform.

[0018] Step S5: Coating and drying the reverse side. The solution containing the carbon fiber balls and adhesive is sprayed onto the reverse side of the attachment mesh through a coating gun and dried. After the drying process, the solvent in the solution is evaporated, and a coating of carbon fiber balls and adhesive is obtained on the upper and lower surfaces of the attachment mesh.

[0019] Step S6: Separate again by shoveling, and separate the attached mesh from the metal platform again.

[0020] The metal stage has a smooth surface, which means that the surface roughness Ra value is less than 0.02. Since the mesh is a porous structure, the coating solution will penetrate into the metal stage through the mesh. The smooth surface of the metal stage is required to reduce the adhesion between the coating and the surface of the metal stage after coating and drying, so as to facilitate separation and obtain a complete coating.

[0021] The solvent used in step S2 is water, and the binder is polyvinylidene fluoride. The mass ratio of the binder to the carbon fiber balls in the coating is 0.2-0.4. When the mass ratio is less than 0.2, powder is easily shed during the process of attaching the mesh and carbon fiber balls to the surface of the inner support and during the painting process, which does not meet the product quality requirements. When the mass ratio is greater than 0.4, a large amount of binder will fill the gaps between the carbon fiber balls and the voids inside the carbon fiber balls, reducing the deformation ability and slippage ability of the carbon fiber balls, thus making the impact buffering ability not meet the quality requirements.

[0022] The bottom of the metal platform is equipped with rollers, which have a locking device. During the coating process in steps S2 and S5, the rollers are locked. After coating in steps S2 and S5, during the transfer to the drying oven, the rollers are unlocked to facilitate pushing the metal platform and thus the attached mesh above the metal platform and the mixed layer on the surface of the attached mesh after coating and drying. Since the mixed layer has a high solvent content at this time, it is easy for the mixed layer to flow, which increases the difficulty of transferring it to the drying process after coating. By moving the metal platform synchronously, the problem of insufficient coating uniformity caused by the flow of the mixed chamber is reduced. During the drying process, the rollers are locked.

[0023] In steps S3 and S6, a metal shovel is used to pull the mesh or coating along the contact surface between the mesh and the metal platform. While holding the mesh, the metal shovel is slid along the surface of the metal platform to remove the mesh or coating from the surface of the metal platform. Compared with directly peeling off the mesh with coating on the surface of the metal platform, the shovel separation method reduces the adhesion between the coating and the metal platform caused by the adhesive, and makes it easier to obtain a complete coating structure.

[0024] Step P2 further includes the following step: rolling the composite structure of the attached mesh and coating obtained in step S6. After rolling, the carbon fiber balls can be more tightly connected, preventing the carbon fiber balls from falling off during the painting process. The thickness difference of the composite structure of the attached mesh and coating before and after rolling can be adjusted according to the thickness of the buffer layer, the porosity of the carbon fiber balls, the number of carbon fiber ball layers, and the target buffer stress.

[0025] The method disclosed in this application has the following advantages:

[0026] Because carbon fiber balls have a porous structure and high toughness, they can buffer impact stress when minor impacts occur. When the impact force increases, they can break the paint layer or cause the carbon fiber balls to shift, further buffering the impact stress through the shift of the carbon fiber balls. As long as the inner support is not broken, surface scratches caused by breakage can be repaired by spraying a carbon fiber ball solution containing adhesive and drying it, making repair convenient and effectively increasing the service life of the anti-collision structure. Compared with some existing technologies that use foam to protect the anti-collision structure, the chemical stability of foam is much lower than that of carbon fiber, resulting in a shorter service life than the anti-collision structure of this application. In addition, compared with a buffer layer made of a single fiber layer, the fiber layer cannot form a carbon fiber ball displacement effect, which makes it easy for stress concentration to form at the most severely impacted position during the impact, thus making the support below (or behind) the buffer layer prone to breakage. However, the carbon fiber balls can shift during the impact, which is equivalent to causing the impacting object to slide, thereby buffering the stress concentration.

[0027] Meanwhile, by pre-forming a composite structure with the attached mesh and the coating containing carbon fiber balls, and then using the composite structure to wrap the inner support, the bonding process between the composite structure and the inner support is simplified. By setting the attached mesh between the carbon fiber ball layers, the number of carbon fiber ball layers in the buffer layer is increased. Since the attached mesh does not contact the inner support, the sliding of the carbon fiber balls will also occur on the surface of the inner support, thereby improving the impact buffering capacity. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0029] Figure 1 This is a schematic diagram of the overall anti-collision structure and a schematic diagram of the location of the AA section in this application.

[0030] Figure 2 This application Figure 1 The diagram shows the cross-section of section AA and the enlarged view of section E.

[0031] Figure 3 This application Figure 2 Enlarged view of the position of E in the middle.

[0032] Figure 4 This is an overall flowchart of the method for preparing the anti-collision structure of this application.

[0033] Figure 5 This is a schematic diagram of the mixing state in step P1 of this application.

[0034] Figure 6 This is a schematic diagram of the structure of the spray droplets during step P1 of the spray granulation process in this application.

[0035] Figure 7 This is a schematic diagram of the carbon fiber sphere structure after the spray granulation process in step P1 of this application.

[0036] Figure 8 This is a schematic diagram of step P1 of this application.

[0037] Figure 9 This is a schematic diagram of the process of spraying a solution containing carbon fiber balls onto the surface of the attached mesh.

[0038] Figure 10 This is a schematic diagram of step S1 of this application.

[0039] Figure 11 This is a schematic diagram of the structure after step S2 of this application.

[0040] Figure 12 This is a schematic diagram of the structure after step S3 of this application.

[0041] Figure 13 This is a schematic diagram of the process of spraying a solution containing carbon fiber balls onto the reverse side of the attached mesh.

[0042] Figure 14 This is a schematic diagram of step S4 of this application.

[0043] Figure 15 This is a schematic diagram of step S5 of this application.

[0044] Figure 16 This is a schematic diagram of step S6 of this application.

[0045] Figure 17 This is a schematic diagram of the overall process of step P2 in this application. Implementation

[0046] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention;

[0047] To address the problems existing in the prior art, this application discloses an anti-collision structure 1, which includes an inner support 11, a buffer layer 12, and a paint layer 13. The buffer layer 12 is disposed on the outer surface of the inner support 11, and the paint layer 13 is disposed on the outer surface of the buffer layer 12.

[0048] The buffer layer 12 is provided with a mesh 14 and multiple carbon fiber balls 121.

[0049] An adhesive is provided between the carbon fiber balls 121 in the buffer layer 12. The buffer layer 12 contains at least four layers of carbon fiber balls 121. The auxiliary mesh 14 is disposed between the carbon fiber balls 121 in the buffer layer 12. The auxiliary mesh 14 has carbon fiber balls 121 on both its upper and lower sides, with the same number of layers on both sides. The carbon fiber 23 is mainly composed of carbon elements and can be made from acrylic fiber and viscose fiber through high-temperature oxidation and carbonization. It possesses high-temperature resistance and abrasion resistance. With its excellent friction resistance, thermal conductivity, and corrosion resistance, carbon fiber 23 is fibrous and flexible. Due to its graphite microcrystalline structure preferentially oriented along the fiber axis, it exhibits high strength and modulus along the fiber axis. Carbon fiber 23 also includes multi-walled carbon nanotubes (MWCNTs), which have been shown to have superior spheroidizing properties during spray granulation. The diameter of carbon fiber 23 ranges from 100 nm to 10 μm, while the diameter of carbon fiber spheres 121 ranges from 5 to 50 μm. The optimal sphere size can be determined based on the solution concentration (the content of carbon fiber 23 in the solution) and the nozzle orifice of the spray gun during spray granulation. The diameter of the carbon fiber ball 121 is adjusted by its size. Since the carbon fiber ball 121 has a porous structure and high toughness, it can buffer the impact stress when a slight impact occurs. When the impact force increases, it can break the paint layer 13 and cause the carbon fiber ball 121 to shift. The shift of the carbon fiber ball 121 further buffers the impact stress. As long as the inner support 11 is not broken, the surface scratches caused by the break can be repaired by spraying a carbon fiber ball 121 solution containing adhesive and drying it. This makes repair convenient and improves the service life of the anti-collision structure 1. Compared with some existing technologies that use foam to protect the outside of the anti-collision structure 1, the service life of the anti-collision structure 1 is not as high as that of the anti-collision structure 1 of this application because the chemical stability of the foam is much lower than that of the carbon fiber 23. In addition, compared with the buffer layer 12 being a solid fiber layer, the fiber layer cannot form the function of shifting the carbon fiber ball 121. Therefore, the fiber layer is prone to stress concentration at the most severe impact position during the impact, which can easily cause the support below (or behind) the buffer layer 12 to break.

[0050] The method for preparing the anti-collision structure 1 includes the following steps:

[0051] Step P1: Prepare carbon fiber spheres 121;

[0052] Step P2: Place the carbon fiber ball 121 on the surface of the inner support 11;

[0053] Step P3: Apply paint layer 13 to the surface of carbon fiber ball 121.

[0054] Step P1 includes the following steps:

[0055] Step F1, mixing: carbon fiber 23 and aqueous solution 22 are placed in mixing container 21 and ultrasonically stirred until homogeneous;

[0056] Step F2, spray granulation: The liquid in the mixed solution is spray-dried using a spray drying device to obtain the first carbon fiber ball 121. The spray drying process is as follows: the spray drying device adsorbs the mixed solution through a pipe to a high-temperature nozzle. The high-temperature nozzle has many tiny nozzles. The mixed solution in the high-temperature nozzle is sprayed out through the tiny nozzles under high pressure to form water droplets 24. The water droplets 24 contain carbon fibers 23. An air supply device is set outside the high-temperature nozzle. After passing through the air supply device and high-temperature and high-pressure spraying, the water in the water droplets 24 is rapidly evaporated. At the same time, the carbon fibers 23 in the atomized droplets agglomerate into carbon fiber balls 121.

[0057] Step P2 includes the following process:

[0058] Step S1: Lay the auxiliary net 14 on the metal platform 41.

[0059] Step S2: Coating and drying. The solution containing the carbon fiber balls 121 and the adhesive is sprayed onto the upper surface of the attachment 14 through the coating gun 42 and dried. After the drying process, the solvent in the solution is evaporated, and a coating of carbon fiber balls 121 and adhesive is obtained on the upper surface of the attachment 14.

[0060] Step S3: Separate by shovel, separating the attached mesh 14 from the metal platform 41;

[0061] Step S4: Lay the metal platform 41 on the reverse side. Turn the attached mesh 14 with the coating on the upper surface over and lay it on the metal platform 41. At this time, the reverse side of the attached mesh 14 is facing up, and the coating on the lower surface of the attached mesh 14 is in contact with the metal platform 41.

[0062] Step S5: Coating and drying the reverse side. The solution containing the carbon fiber balls 121 and the adhesive is sprayed onto the reverse side of the attachment 14 through the coating gun 42 and dried. After the drying process, the solvent in the solution is evaporated, and the carbon fiber balls 121 and the adhesive coating are adhered to the upper and lower surfaces of the attachment 14.

[0063] Step S6: Separate again by shoveling, and separate the attached net 14 from the metal platform 41 again.

[0064] The surface of the metal platform 41 is smooth, which means that the surface roughness Ra value is less than 0.02. Since the attachment mesh 14 has a porous structure, the coating solution will penetrate into the metal platform 41 through the attachment mesh 14. The smooth surface of the metal platform 41 is required to reduce the adhesion between the coating and the surface of the metal platform 41 after coating and drying, so as to facilitate separation and obtain a complete coating.

[0065] The solvent used in step S2 is water, and the binder is polyvinylidene fluoride. The mass ratio of the binder to the carbon fiber balls 121 in the coating is between 0.2 and 0.4. When the mass ratio is less than 0.2, powder is easily shed during the process of attaching the mesh 14 and the carbon fiber balls 121 to the surface of the inner support 11 and during the painting process, which does not meet the product quality requirements. When the mass ratio is greater than 0.4, a large amount of binder will fill the gaps between the carbon fiber balls 121 and the voids inside the carbon fiber balls 121, which reduces the deformation ability and sliding ability of the carbon fiber balls 121, thus making the impact buffering ability not meet the quality requirements.

[0066] The bottom of the metal platform 41 is equipped with rollers, which are equipped with locking devices. During the coating process in steps S2 and S5, the rollers are locked. During the transfer to the drying oven after coating in steps S2 and S5, the rollers are unlocked to facilitate pushing the metal platform 41 and thus the auxiliary mesh 14 above the metal platform 41 and the mixed layer coated and dried on the surface of the auxiliary mesh 14. Since the mixed layer has a high solvent content at this time, it is easy for the mixed layer to flow, which increases the difficulty of transferring it to the drying process after coating. By moving the metal platform 41 synchronously, the problem of insufficient coating uniformity caused by the flow of the mixing chamber is reduced. During the drying process, the rollers are locked.

[0067] In steps S3 and S6, a metal spatula is used to pull the mesh 14 or coating along the contact surface with the metal platform 41. While holding the mesh 14, the metal spatula is slid along the surface of the metal platform 41 to remove the mesh 14 or coating from the surface of the metal platform 41. Compared with directly peeling off the coated mesh 14 from the surface of the metal platform 41, the spatula separation method reduces the adhesion between the coating and the metal platform 41 caused by the adhesive, and makes it easier to obtain a complete coating structure.

[0068] Step P2 further includes the following step: rolling the attached mesh 14 and the coating composite structure obtained in step S6. After rolling, the carbon fiber balls 121 can be more tightly connected, preventing the carbon fiber balls 121 from falling off during the painting process. The thickness difference between the attached mesh 14 and the coating composite structure before and after rolling can be adjusted according to the thickness of the buffer layer 12, the porosity of the carbon fiber balls 121, the number of layers of carbon fiber balls 121, and the target buffer stress.

[0069] The method disclosed in this application has the following advantages:

[0070] Because the carbon fiber balls 121 have a porous structure and high toughness, they can buffer impact stress when a minor impact occurs. When the impact force increases, they can break through the paint layer 13 and cause the carbon fiber balls 121 to shift, further buffering the impact stress through the shift of the carbon fiber balls 121. As long as the inner support 11 is not broken, the surface scratches caused by the breakage can be repaired by spraying a carbon fiber ball 121 solution containing adhesive and drying it, thus making repair convenient and effectively increasing the service life of the anti-collision structure 1. Compared with some existing technologies, the outer surface of the anti-collision structure 1 is... The foam material has a lower chemical stability than carbon fiber 23, resulting in a shorter service life compared to the anti-collision structure 1 of this application. Furthermore, compared to setting the buffer layer 12 as a single piece of fiber, the fiber layer cannot form the displacement effect of the carbon fiber balls 121. This makes it easy for stress concentration to form at the most severe impact point during the impact, which can easily cause the support below (or behind) the buffer layer 12 to break. In contrast, the carbon fiber balls 121 can be displaced during the impact, which is equivalent to causing the impacting object to slide, thereby reducing stress concentration during the buffering process.

[0071] Meanwhile, by pre-forming a composite structure between the attached mesh 14 and the coating containing carbon fiber balls 121, and then using the composite structure to wrap around the inner support 11, the bonding process between the composite structure and the inner support 11 is simplified. By setting the attached mesh 14 between the carbon fiber ball 121 layers, the number of carbon fiber ball 121 layers in the buffer layer 12 is increased. Since the attached mesh 14 does not contact the inner support 11, the sliding of the carbon fiber balls 121 will also occur on the surface of the inner support 11, thereby improving the impact buffering capacity.

[0072] The foregoing should be understood as follows: these embodiments are only used to illustrate the present invention more clearly, and are not intended to limit the scope of the present invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art fall within the scope defined by the appended claims.

Claims

1. A method of manufacturing a crash structure, characterized by, The method comprises the following steps: Step P1, preparing carbon fiber balls; Step P2, setting carbon fiber balls on the surface of the inner support body; Step P3, setting a paint layer on the surface of the carbon fiber balls, Wherein, the anti-collision structure prepared by the method comprises an inner support body, a buffer layer, and a paint layer, the buffer layer is arranged on the outer surface of the inner support body, and the paint layer is arranged on the outer surface of the buffer layer; The buffer layer is provided with an auxiliary net and a plurality of layers of carbon fiber balls, The buffer layer is provided with an adhesive between the carbon fiber balls, the buffer layer is provided with at least four layers of carbon fiber balls, the auxiliary net is arranged between the carbon fiber balls in the buffer layer, the carbon fiber balls are arranged on the upper and lower sides of the auxiliary net, the number of layers of the carbon fiber balls on the upper and lower sides of the auxiliary net is the same, The step P1 comprises the following steps: Step F1, mixing, arranging carbon fibers and an aqueous solution in a mixing container and uniformly stirring by ultrasonic agitation; Step F2, spray granulation, using a spray drying device to spray dry the liquid in the mixed solution to obtain first carbon fiber balls, The step P2 comprises the following processes: Step S1, auxiliary net laying metal table, laying the auxiliary net on the metal table; Step S2, coating and drying, spraying the solution containing the carbon fiber balls and the adhesive to the upper surface of the auxiliary net by the coating gun and drying; Step S3, shovel separation, separating the auxiliary net from the metal table; Step S4, reverse laying metal table, laying the auxiliary net with the coating on the upper surface on the metal table after turning over, at this time the auxiliary net is upward, and the coating on the lower surface of the auxiliary net contacts the metal table; Step S5, coating and drying, spraying the solution containing the carbon fiber balls and the adhesive to the reverse side of the auxiliary net by the coating gun and drying; Step S6, again shovel separation, again separating the auxiliary net from the metal table, The solvent of the solution used in the step S2 is water, the adhesive is polyvinylidene fluoride, and the mass ratio of the adhesive to the carbon fiber balls in the coating is 0.2-0.

4.

2. The method of claim 1, wherein the method further comprises: The surface of the metal table is smooth.

3. The method of claim 2, wherein the method further comprises: The bottom of the metal table is provided with a roller, the roller is provided with a locking device, the roller is locked during the coating process of the step S2 and the step S5, the roller is unlocked during the transportation to the oven after the coating of the step S2 and the step S5, and the roller is locked during the drying process.

4. The method of claim 3, wherein the method further comprises: The metal shovel is used along the contact surface between the auxiliary net or the coating and the metal table during the steps S3 and S6, the auxiliary net is pulled while the metal shovel slides along the surface of the metal table, so that the auxiliary net or the coating on the surface of the metal table is removed.

5. The method of claim 4, wherein the method further comprises: The step P2 further comprises the following step: rolling the auxiliary net and the coating composite structure obtained in the step S6.

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