A rocker panel and vehicle

Abstract

The utility model embodiment provides a kind of bottom guard plate and vehicle, belong to bottom guard plate technical field.The bottom guard plate includes upper fiber reinforced resin layer, rigid layer and lower fiber reinforced resin layer, the rigid layer is located between the upper fiber reinforced resin layer and the lower fiber reinforced resin layer, and the upper fiber reinforced resin layer and the lower fiber reinforced resin layer satisfy the following conditions:0.1≤d 上 / d 下 <0.4, d 下 It is 1.8mm~2.0mm, wherein, d 上 It is the thickness of the upper fiber reinforced resin layer, unit is mm, d 下 It is the thickness of the lower fiber reinforced resin layer, unit is mm.The bottom guard plate has good impact resistance, and gives consideration to the purpose of air, moisture, insulation, comprehensive protection effect is good, can satisfy the multiple requirements of battery pack protection.

Description

Technical Field

[0001] This utility model belongs to the technical field of underbody protection plates, specifically relating to an underbody protection plate and a vehicle. Background Technology

[0002] With the rapid development of electric vehicles, people are placing increasingly higher demands on their safety performance. As the power source for electric vehicles, the safety of the power battery is crucial. In electric vehicles, the battery pack is usually located under the vehicle's chassis, connected to the chassis by bolts, with its lower surface exposed. During vehicle operation, the bottom of the battery pack is susceptible to impacts from bumps and flying stones. To improve the safety of the battery pack, a bottom protection plate is usually installed at the bottom of the battery pack.

[0003] Currently, common battery pack bottom protection solutions primarily use steel plates as the protective material. However, steel plates can produce rattling noises when in contact with foreign objects, affecting the passenger experience. Furthermore, steel plates are prone to rust and corrosion, requiring a rust-proof coating on the outside, but the adhesion of this coating to the steel plate is relatively low. To address this issue, existing technologies typically use a bottom protection plate made of steel plate with a PVC coating. However, the PVC coating has poor impact resistance and is easily detached upon impact, leading to corrosion of the steel plate over long-term use.

[0004] Common battery pack bottom protection plates can also use plastic sheets as protective materials. However, although plastic sheets are not easily corroded during long-term use, their strength is insufficient to provide effective protection for the battery pack when subjected to impact.

[0005] In recent years, some novel materials, such as resin-based fiber underbody panels, have been applied to the manufacture of battery underbody panels. For example, patent application CN117343487A discloses a wear-resistant and impact-resistant automotive underbody panel and its molding method. The automotive underbody panel is made from a resin-based glass fiber underbody panel, which comprises a resin composition and long glass fibers, with the long glass fibers accounting for 10-50% of the total mass of the resin composition and long glass fibers. The resin composition includes bisphenol epoxy resin, anhydride curing agents, toughening compositions, diluents, antioxidants, amine accelerators, imidazole accelerators, defoamers, and coupling agents. Although underbody panels made from such resin-based fiber underbody panels have high strength, their impact resistance is still insufficient and cannot meet the multiple requirements for battery pack protection. Utility Model Content

[0006] This utility model aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this utility model propose a bottom guard plate and a vehicle. This bottom guard plate can achieve good impact resistance, effectively protecting the battery pack when impacted. Furthermore, the bottom guard plate can also isolate air and moisture, and provide insulation, meeting multiple requirements for battery pack protection.

[0007] This utility model embodiment provides a bottom protective plate, which includes an upper fiber-reinforced resin layer, a rigid body layer, and a lower fiber-reinforced resin layer. The rigid body layer is located between the upper fiber-reinforced resin layer and the lower fiber-reinforced resin layer, and the upper fiber-reinforced resin layer and the lower fiber-reinforced resin layer satisfy the following condition: 0.1≤d 上 / d 下 <0.4, d 下 The thickness is 1.8mm to 2.0mm, where d 下 The thickness of the lower fiber-reinforced resin layer is expressed in mm; d 上 The thickness of the upper fiber-reinforced resin layer is expressed in mm.

[0008] The advantages and technical effects of the bottom protective plate in this embodiment of the utility model are as follows: (1) The function of the upper fiber-reinforced resin layer is to isolate air, moisture, etc., thereby protecting the rigid body layer, reducing the risk of the rigid body layer being corroded, extending the service life of the bottom protective plate, and also achieving the purpose of insulation to ensure the safe operation of the battery pack.

[0009] (2) The function of the lower fiber reinforced resin layer is to improve the impact resistance of the bottom protective plate, and at the same time, it can also be used to isolate air, moisture and insulation.

[0010] (3) Therefore, considering the above effects, the upper fiber-reinforced resin layer should be as thin as possible, and the lower fiber-reinforced resin layer should be as thick as possible (d 下 (The thickness is 1.8mm to 2.0mm), and considering factors such as cost, the final value was determined to be 0.1≤d. 上 / d 下 <0.4.

[0011] In some embodiments, the upper fiber-reinforced resin layer and the lower fiber-reinforced resin layer satisfy the following condition: 0.3 ≤ d 上 / d 下 <0.4.

[0012] In some embodiments, the thickness d of the upper fiber-reinforced resin layer 上 The thickness is 0.1 mm to 0.8 mm. Preferably, the thickness d of the upper fiber-reinforced resin layer is... 上 The thickness is 0.5mm to 0.8mm.

[0013] In some embodiments, the thickness d of the lower fiber-reinforced resin layer 下 The thickness ranges from 0.5mm to 4.0mm.

[0014] In some embodiments, the upper fiber-reinforced resin layer includes at least one of a fiber-reinforced polyurethane resin layer, a fiber-reinforced epoxy resin layer, a fiber-reinforced vinyl resin layer, a fiber-reinforced polyurethane-modified epoxy resin layer, a fiber-reinforced polyurethane-modified vinyl resin layer, and a fiber-reinforced epoxy-modified vinyl resin layer.

[0015] In some embodiments, the elastic modulus of the upper fiber-reinforced resin layer in the 0˚ direction is 0.5 GPa to 30 GPa.

[0016] In some embodiments, the density of the upper fiber-reinforced resin layer is 1.5 g / cm³. 3 ~2.1g / cm 3 .

[0017] In some embodiments, the lower fiber-reinforced resin layer includes at least one of a fiber-reinforced polyurethane resin layer, a fiber-reinforced epoxy resin layer, a fiber-reinforced vinyl resin layer, a fiber-reinforced polyurethane-modified epoxy resin layer, a fiber-reinforced polyurethane-modified vinyl resin layer, and a fiber-reinforced epoxy-modified vinyl resin layer.

[0018] In some embodiments, the elastic modulus of the lower fiber-reinforced resin layer in the 0˚ direction is 0.5 GPa to 30 GPa.

[0019] In some embodiments, the density of the lower fiber-reinforced resin layer is 1.5 g / cm³. 3 ~2.1g / cm 3 .

[0020] In some embodiments, the rigid body layer has a flexural modulus ≥80 GPa in the 0˚ direction.

[0021] Optionally, the rigid layer includes at least one of a metal plate, a plastic plate, and a high-rigidity composite plate.

[0022] Optionally, the thickness of the rigid body layer is 0.4 mm to 1.5 mm.

[0023] In some embodiments, the thickness of the bottom protective plate is 1.5 mm to 5.0 mm.

[0024] Secondly, this utility model embodiment also provides a vehicle, the vehicle including a battery pack and a bottom protection plate, the bottom protection plate being the bottom protection plate described in the first aspect, the upper fiber-reinforced resin layer of the bottom protection plate being opposite to the battery pack.

[0025] The advantages and technical effects of the vehicle according to this utility model embodiment are as follows: Because of the underbody protection plate described in the first aspect, the vehicle of this utility model embodiment has all the advantages brought by the underbody protection plate described in the first aspect, which will not be repeated here. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of a bottom protective plate according to an embodiment of the present utility model.

[0027] Explanation of reference numerals in the attached figures: 1-Bottom protective plate; 11-Upper fiber reinforced resin layer; 12-Rigid body layer; 13-Lower fiber reinforced resin layer; 2-Battery pack. Detailed Implementation

[0028] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0029] In the description of this utility model, it should be understood that the terms "upper", "lower", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0030] In a first aspect, this utility model embodiment provides a bottom protective plate 1, such as... Figure 1 As shown, the bottom protective plate includes an upper fiber-reinforced resin layer 11, a rigid body layer 12, and a lower fiber-reinforced resin layer 13. The rigid body layer 12 is located between the upper fiber-reinforced resin layer 11 and the lower fiber-reinforced resin layer 13, and the upper fiber-reinforced resin layer 11 and the lower fiber-reinforced resin layer 13 satisfy the following condition: 0.1 ≤ d 上 / d 下 <0.4, d 下 The thickness is 1.8mm to 2.0mm, where d 上 The thickness of the upper fiber-reinforced resin layer 11 is expressed in mm (d). 下 The thickness of the lower fiber-reinforced resin layer 13 is in mm.

[0031] It should be clarified that the rigid layer 12 has a first side close to the battery pack 2 and a second side away from the battery pack 2. The upper fiber-reinforced resin layer 11 is disposed on the first side of the rigid layer 12 close to the battery pack 2, and the lower fiber-reinforced resin layer 13 is disposed on the second side of the rigid layer 12 away from the battery pack 2. That is to say, when the bottom guard plate is impacted, the lower fiber-reinforced resin layer 13 is the first layer to be hit by the impacting object, while the upper fiber-reinforced resin layer 11 is the layer disposed between the rigid layer 12 and the battery pack 2.

[0032] The upper fiber-reinforced resin layer 11 serves to isolate the rigid layer 12 from air and moisture, thereby protecting it, reducing the risk of corrosion, and extending the service life of the bottom protective plate 1. It also provides insulation, ensuring the safe operation of the battery pack. The lower fiber-reinforced resin layer 13 improves the impact resistance of the bottom protective plate 1, while also providing air and moisture isolation and insulation. Through extensive experiments, the inventors discovered that, with the same total material usage, the thickness d of the upper fiber-reinforced resin layer 11... 上 The thickness d of the lower fiber-reinforced resin layer 13 下 The relationship between these factors affects the overall protective performance of the bottom protective plate 1. The thickness of the fiber-reinforced resin layer and the overall protective performance of the bottom protective plate 1 are not simply additive; doubling the thickness of the fiber-reinforced resin layer will result in more than a doubling of the overall protective performance of the bottom protective plate 1. Therefore, considering the roles of the upper fiber-reinforced resin layer 11 and the lower fiber-reinforced resin layer 13, under the condition of the same total material usage, the upper fiber-reinforced resin layer 11 should be as thin as possible, and the lower fiber-reinforced resin layer 13 should be as thick as possible (d...). 下 (The thickness is 1.8mm to 2.0mm). Considering process limitations, the final value was determined to be 0.1≤d. 上 / d 下 <0.4.

[0033] When the thickness d of the fiber-reinforced resin layer 11 上 The thickness d of the lower fiber-reinforced resin layer 13 下 Satisfying 0.1≤d 上 / d 下 <0.4 (e.g., d) 上 / d 下 When d equals 0.1, 0.12, 0.15, 0.18, 0.2, 0.22, 0.25, 0.28, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.38, 0.39, etc., the bottom protective plate 1 has good overall protection performance and can meet the multiple requirements for battery pack protection. 上 / d 下When the thickness is less than 0.1, the bottom protective plate 1 is insufficient in isolating air and moisture, making it difficult to effectively protect the rigid body layer 12. From an economic perspective, the fiber-reinforced resin layer cannot be increased indefinitely to achieve better impact resistance. Given that the total thickness of the upper fiber-reinforced resin layer 11 and the lower fiber-reinforced resin layer 13 is the same, relative to d... 上 / d 下 <0.4, when d 上 / d 下 When the impact resistance is ≥0.4, the impact resistance of the bottom guard plate 1 deteriorates.

[0034] Preferably, the upper fiber-reinforced resin layer 11 and the lower fiber-reinforced resin layer 13 satisfy the following condition: 0.3 ≤ d 上 / d 下 <0.4. When the thickness d of the upper fiber-reinforced resin layer 11 is... 上 The thickness d of the lower fiber-reinforced resin layer 13 下 Satisfying 0.3≤d 上 / d 下 When the value is less than 0.4, the overall protective performance of the bottom guard plate 1 is further improved.

[0035] In some embodiments, the lower fiber-reinforced resin layer d 下 The thickness of the lower fiber-reinforced resin layer 13 is 0.5mm to 4.0mm, for example, 0.5mm, 0.8mm, 1.0mm, 1.2mm, 1.5mm, 1.8mm, 1.82mm, 1.84mm, 1.86mm, 1.88mm, 1.9mm, 1.92mm, 1.94mm, 1.96mm, 1.98mm, 2.0mm, etc. When the thickness of the lower fiber-reinforced resin layer 13 is within the above range, the lower fiber-reinforced resin layer 13 has a larger compression deformation space when the bottom protective plate 1 is impacted, thus absorbing more energy and transferring less impact energy to the rigid body layer 12. This prevents the rigid body layer 12 from deforming and intruding into the battery pack 2, damaging the battery cell. In other words, the lower fiber-reinforced resin layer 13 of this thickness has a good buffering and energy absorption effect, which is beneficial to improving the impact resistance of the bottom protective plate 1. Specifically, preferably, the thickness d of the lower fiber-reinforced resin layer 13 is... 下 The thickness is 1.8mm to 2.0mm.

[0036] In some embodiments, the thickness d of the upper fiber-reinforced resin layer 11 上The thickness ranges from 0.1mm to 0.8mm, for example, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.52mm, 0.55mm, 0.58mm, 0.6mm, 0.62mm, 0.65mm, 0.68mm, 0.7mm, 0.72mm, 0.75mm, 0.78mm, 0.8mm, etc. The upper fiber-reinforced resin layer 11 is disposed between the rigid body layer 11 and the battery pack 2, serving to isolate air and moisture to protect the rigid body layer 12. When the thickness d of the upper fiber-reinforced resin layer 11... 上 If the thickness is too small, it will be difficult to isolate air and moisture to protect the rigid layer 12. However, when the thickness d of the fiber-reinforced resin layer 11 is too small... 上 If the thickness is too large, the overall thickness of the bottom protective plate 1 will be too large, which is not conducive to achieving the lightweight design of the bottom protective plate. Preferably, the thickness d of the upper fiber-reinforced resin layer 11 is... 上 The thickness is 0.5mm to 0.8mm.

[0037] In some embodiments, the upper fiber-reinforced resin layer 11 includes at least one of a fiber-reinforced polyurethane resin layer, a fiber-reinforced epoxy resin layer, a fiber-reinforced vinyl resin layer, a fiber-reinforced polyurethane-modified epoxy resin layer, a fiber-reinforced polyurethane-modified vinyl resin layer, and a fiber-reinforced epoxy-modified vinyl resin layer.

[0038] In some embodiments, the lower fiber-reinforced resin layer 13 includes at least one of a fiber-reinforced polyurethane resin layer, a fiber-reinforced epoxy resin layer, a fiber-reinforced vinyl resin layer, a fiber-reinforced polyurethane-modified epoxy resin layer, a fiber-reinforced polyurethane-modified vinyl resin layer, and a fiber-reinforced epoxy-modified vinyl resin layer.

[0039] In some embodiments, the fibers of the upper fiber-reinforced resin layer 11 and the fibers of the lower fiber-reinforced resin layer 13 each independently include at least one of glass fiber, carbon fiber, polyester fiber, natural fiber, aromatic polyamide fiber, nylon fiber, basalt fiber, boron fiber, silicon carbide fiber, asbestos fiber, whiskers, and metal fiber.

[0040] In some embodiments, the tensile strength of the resin in the upper fiber-reinforced resin layer 11 is 15MPa to 70MPa, for example, 15MPa, 20MPa, 25MPa, 30MPa, 35MPa, 50MPa, 55MPa, 60MPa, 65MPa, 70MPa, etc., the elongation at break is 100% to 300%, for example, 100%, 120%, 140%, 160%, 180%, 200%, 220%, 240%, 260%, 280%, 300%, etc., and the tear strength is 150kN / m to 250kN / m, for example, 150kN / m, 160kN / m, 180kN / m, 200kN / m, 220kN / m, 240kN / m, 250kN / m, etc. When the tensile strength, elongation at break, and tear strength of the resin are within the above range, the high tensile strength, high elongation at break, and high tear strength of the resin described above enable the upper fiber-reinforced resin layer 11 to play a certain role in buffering and absorbing energy during the process of the bottom of the battery pack being damaged by external force.

[0041] In some embodiments, the tensile strength of the resin in the lower fiber-reinforced resin layer 13 is 15MPa to 70MPa, for example, 15MPa, 20MPa, 25MPa, 30MPa, 35MPa, 50MPa, 55MPa, 60MPa, 65MPa, 70MPa, etc.; the elongation at break is 100% to 300%, for example, 100%, 120%, 140%, 160%, 180%, 200%, 220%, 240%, 260%, 280%, 300%, etc.; and the tear strength is 150kN / m to 250kN / m, for example, 150kN / m, 160kN / m, 180kN / m, 200kN / m, 220kN / m, 240kN / m, 250kN / m, etc. Utilizing the high tensile strength, high elongation at break, and high tear strength of the resin described above, the lower fiber-reinforced resin layer 13 plays a good role in buffering and absorbing energy during the process of the bottom of the battery pack being damaged by external forces.

[0042] Optionally, the resin of the upper fiber-reinforced resin layer 11 and the resin of the lower fiber-reinforced resin layer 13 may each independently include at least one of polyurethane resin, epoxy resin, vinyl ester resin, polyurethane-modified epoxy resin, polyurethane-modified vinyl ester resin, and epoxy-modified vinyl ester resin. The tensile strength of the resins listed above can meet the requirements of 30 MPa to 70 MPa, the elongation at break can meet the requirements of 100% to 300%, and the tear strength can meet the requirements of 150 kN / m to 250 kN / m. The resulting upper fiber-reinforced resin layer 11 and lower fiber-reinforced resin layer 13 possess excellent buffering and energy absorption properties.

[0043] Preferably, the resin in the upper fiber-reinforced resin layer 11 and the resin in the lower fiber-reinforced resin layer 13 are polyurethane resins. Compared to the other resins listed above, when the resin is a polyurethane resin, the buffering and energy absorption effect of the upper fiber-reinforced resin layer 11 and the lower fiber-reinforced resin layer 13 is better.

[0044] More preferably, the raw materials for preparing the polyurethane resin include an isocyanate component and an isocyanate reactive component; the isocyanate reactive component includes a polyol component, a chain extender, and optional additives; the polyol component includes a polyol with a linear structure and an average functionality of 2-3. Compared with ordinary polyurethane resins in related technologies, the polyurethane resin described above has superior impact resistance, scratch resistance, and puncture resistance, which is more conducive to improving the overall performance of the upper fiber-reinforced resin layer 11 and the lower fiber-reinforced resin layer 13.

[0045] Optionally, the mass of the polyol with a linear structure accounts for 30 wt.% to 80 wt.% of the total mass of the isocyanate reactive component; preferably 40 wt.% to 70 wt.%; preferably, the molar ratio of -NCO groups in the isocyanate component to -OH groups in the isocyanate reactive component is 1.0 to 1.5; preferably, the mass ratio of the isocyanate component to the isocyanate reactive component is 0.5 to 2.0; preferably, the isocyanate component is a liquid at 25°C with a viscosity of 100 cp to 1000 cp; preferably, the NCO content in the isocyanate component is 12 wt.% to 35 wt.%; preferably, the isocyanate component includes at least one of MDI, hexamethylene diisocyanate, isophorone diisocyanate, phenylenediamine diisocyanate, 1,5-naphthalene diisocyanate, modified isocyanate, or polymers of the above isocyanates.

[0046] The modified isocyanate is an alcohol-modified isocyanate, wherein the alcohol includes polymeric polyols or small molecule polyols; preferably, the polymeric polyol includes at least one of polyester polyols, polyether polyols, polycaprolactone, polycarbonate polyols, and polyethylene glycol; preferably, the small molecule polyol includes at least one of diethylene glycol, dipropylene glycol, ethylene glycol, and glycerol; preferably, the modified isocyanate is selected from at least one of MDI, hexamethylene diisocyanate, isophorone diisocyanate, phenylenediamine diisocyanate, and 1,5-naphthalene diisocyanate; preferably, the modified isocyanate is obtained by reacting an alcohol with a polyisocyanate; preferably, the mass of the modified isocyanate in the isocyanate component is 30 wt.% to 80 wt.% of the total mass of the isocyanate component; more preferably, the mass fraction is 50 wt.% to 75 wt.%. More preferably, the modified isocyanate is modified MDI; preferably, the modified MDI has a weight-average molecular weight of 500 to 2500 and an average functionality of 2 to 3.

[0047] Optionally, the hydroxyl value of the isocyanate reactive component is 300 mg KOH / g to 600 mg KOH / g; optionally, the isocyanate reactive component is a liquid at 25°C with a viscosity of 100 cp to 2000 cp; optionally, the polyol component comprises a polyol with a linear structure and an average functionality of 2 to 3; preferably, the weight-average molecular weight of the polyol with a linear structure is 600 to 10000, more preferably 1000 to 4000; optionally, the hydroxyl value of the polyol with a linear structure is 10 mg KOH / g. The KOH / g to 300 mg KOH / g concentration has a viscosity of less than 5000 cp at 40°C. Optionally, the polyol with a linearly regular structure includes at least one of polytetrahydrofuran polyol, modified polytetrahydrofuran polyol, polyethylene glycol, modified polyethylene glycol, polyester polyol, modified polyester polyol, polycaprolactone polyol, modified polycaprolactone polyol, polycarbonate polyol, and modified polycarbonate polyol. Preferably, the polyol with a linearly regular structure is polyester polyol, polytetrahydrofuran polyol, polyethylene glycol, or polycaprolactone polyol. At least one of polyols and polycarbonate polyols, more preferably, the polyol having a linear regular structure is a polyester polyol or a polytetrahydrofuran polyol; the modified polytetrahydrofuran polyol refers to a fluorinated or siloxane-modified polytetrahydrofuran polyol, the modified polyethylene glycol refers to a fluorinated or siloxane-modified polytetrahydrofuran polyol, the modified polyester polyol refers to a fluorinated or siloxane-modified polyester polyol, the modified polycaprolactone polyol refers to a fluorinated or siloxane-modified polycaprolactone polyol, and the modified polycarbonate polyol refers to a fluorinated or siloxane-modified polycaprolactone polyol. The polycarbonate polyol is a non-linear polyol; optionally, the polyol component further includes other polyols, wherein the average functionality of the other polyols is 3 to 5 and the weight-average molecular weight is 300 to 5000; optionally, the mass of the other polyols is 5 wt.% to 30 wt.% of the total mass of the isocyanate reactive components; optionally, the other polyols include at least one of non-linear polyether polyols, non-linear polyester polyols, and non-linear polyether ester polyols, preferably, the other polyols are non-linear polyether polyols and / or non-linear polyester polyols.

[0048] Optionally, the chain extender has an average functionality of 2-4 and a molecular weight of 62-200; optionally, the chain extender has a mass of 10 wt.% to 35 wt% of the total mass of the isocyanate reactive components; optionally, the chain extender is selected from at least one of ethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1-pentanediol, hexanediol, diethylene glycol, triethylene glycol, dipropylene glycol, diethylene glycol, neopentanediol, glycerol, trimethylolpropane, and pentaerythritol, preferably ethylene glycol, 1,4-butanediol, or glycerol; more preferably, the chain extender includes ethylene glycol, and the mass of ethylene glycol is more than 5 wt% of the total mass of the isocyanate reactive components.

[0049] Optionally, the additives in the isocyanate reactive component include at least one of the following: color paste, water absorbent, inorganic filler, internal mold release agent, antioxidant, light stabilizer, auxiliary antioxidant, hydrolysis stabilizer, defoamer, foaming agent, stabilizer, bactericide and mildew inhibitor, reactive diluent, coupling agent, dehydrating agent, polymerization inhibitor, flame retardant, and catalyst; preferably, the mass of the additives is 0.05 wt.% to 40 wt.% of the total mass of the isocyanate reactive component.

[0050] In some embodiments, based on a total mass of 100 wt.% of the fiber-reinforced resin layer 11, the fiber content is 5 wt.% to 70 wt.%, for example, 5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%, 25 wt.%, 30 wt.%, 35 wt.%, 40 wt.%, 45 wt.%, 50 wt.%, 55 wt.%, 60 wt.%, 65 wt.%, 70 wt.%, etc.; and the resin content is 30 wt.% to 95 wt.%, for example, 30 wt.%, 35 wt.%, 40 wt.%, 45 wt.%, 50 wt.%, 55 wt.%, 60 wt.%, 65 wt.%, 70 wt.%, 75 wt.%, 80 wt.%, 85 wt.%, 90 wt.%, 95 wt.%, etc. Meeting these conditions helps the fiber-reinforced resin layer 11 to simultaneously achieve good buffering and energy absorption, strength, and rigidity.

[0051] In some embodiments, based on the total mass of the fiber-reinforced resin layer 13 (100 wt.%), the fiber content is 5 wt.% to 70 wt.%, for example, 5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%, 25 wt.%, 30 wt.%, 35 wt.%, 40 wt.%, 45 wt.%, 50 wt.%, 55 wt.%, 60 wt.%, 65 wt.%, 70 wt.%, etc.; the resin content is 30 wt.% to 95 wt.%, for example, 30 wt.%, 35 wt.%, 40 wt.%, 45 wt.%, 50 wt.%, 55 wt.%, 60 wt.%, 65 wt.%, 70 wt.%, 75 wt.%, 80 wt.%, 85 wt.%, 90 wt.%, 95 wt.%, etc. Meeting these conditions helps the fiber-reinforced resin layer 13 to simultaneously achieve good buffering energy absorption, strength, and rigidity.

[0052] In some embodiments, the elastic modulus of the upper fiber-reinforced resin layer 11 in the 0˚ direction is 0.5 GPa to 30 GPa, for example, 0.5 GPa, 1.0 GPa, 2.0 GPa, 3 GPa, 5 GPa, 10 GPa, 12 GPa, 15 GPa, 18 GPa, 20 GPa, 22 GPa, 25 GPa, 28 GPa, 30 GPa, etc., preferably 3 GPa to 30 GPa. The smaller the elastic modulus, the easier it is to deform and absorb energy. The elastic modulus of the upper fiber-reinforced resin layer 11 in the 0˚ direction is within the above range, which is beneficial to improving the buffering and energy absorption effect of the upper fiber-reinforced resin layer 11.

[0053] In some embodiments, the elastic modulus of the lower fiber-reinforced resin layer 13 in the 0˚ direction is 0.5 GPa to 30 GPa, for example, 0.5 GPa, 1.0 GPa, 2.0 GPa, 3 GPa, 5 GPa, 10 GPa, 12 GPa, 15 GPa, 18 GPa, 20 GPa, 22 GPa, 25 GPa, 28 GPa, 30 GPa, etc., preferably 3 GPa to 30 GPa. The smaller the elastic modulus, the easier it is to deform and absorb energy. The elastic modulus of the lower fiber-reinforced resin layer 13 in the 0˚ direction is within the above range, which is beneficial to improving the buffering and energy absorption effect of the lower fiber-reinforced resin layer 13.

[0054] In some embodiments, the density of the upper fiber-reinforced resin layer 11 is 1.5 g / cm³. 3 ~2.1 g / cm 3 For example, 1.5g / cm 3 1.6g / cm 3 1.7g / cm 3 1.8g / cm 3 1.9g / cm 3 2.0g / cm3 2.1g / cm 3 Meeting the above conditions helps reduce the weight of the bottom guard plate itself.

[0055] In some embodiments, the density of the lower fiber-reinforced resin layer 13 is 1.5 g / cm³. 3 ~2.1 g / cm 3 For example, 1.5g / cm 3 1.6g / cm 3 1.7g / cm 3 1.8g / cm 3 1.9g / cm 3 2.0g / cm 3 2.1g / cm 3 Meeting the above conditions helps reduce the weight of the bottom guard plate itself.

[0056] In some embodiments, the rigid layer 12 includes at least one of a metal plate, a plastic plate, and a high-rigidity composite plate. The metal plate includes, but is not limited to, at least one of a steel plate, an iron plate, an aluminum plate, and a titanium plate. The surface of the metal plate may be uncoated or coated, and the coating may be, for example, at least one of a galvanized layer, a galvanized iron alloy layer, and an electrophoretic paint protective layer. Based on the presence of the upper fiber-reinforced resin layer 11 and the lower fiber-reinforced resin layer 13, the metal plate can eliminate the need for coatings such as the galvanized layer, the galvanized iron alloy layer, and the electrophoretic paint protective layer, as well as the insulating layer, achieving further cost reduction compared to existing solutions. The metal plate may be an untreated metal plate or a pretreated metal plate. Pretreatment may include sandblasting, shot blasting followed by degreasing and dust removal, or plasma treatment, etc. The plastic plate may include, but is not limited to, at least one of a polyetheretherketone (PEEK) plate, a polypropylene (PP) plate, a polyethylene (PE) plate, a polyamide (PA, nylon) plate, a polycarbonate (PC) plate, an acrylonitrile-butadiene-styrene copolymer (ABS) plate, and a polyvinyl chloride (PVC) plate. High-rigidity composite panels may be composed of at least two of the following: aramid fiber, high molecular weight polyethylene fiber, and basalt fiber.

[0057] In some embodiments, the flexural modulus of the rigid layer 12 in the 0˚ direction is ≥80 GPa, such as 80 GPa, 85 GPa, 90 GPa, 95 GPa, 100 GPa, 105 GPa, 110 GPa, 115 GPa, 120 GPa, 140 GPa, 160 GPa, 180 GPa, 200 GPa, 220 GPa, 240 GPa, 260 GPa, 280 GPa, 300 GPa, etc. Meeting these conditions helps the rigid layer 12 to be less prone to bending or deformation under stress, better maintain its original shape, improve the rigidity of the rigid layer 12, and better absorb and disperse impact forces, thereby enhancing the safety of the bottom protective plate 1.

[0058] In some embodiments, the thickness of the rigid body layer 12 is 0.4 mm to 1.5 mm, such as 0.4 mm, 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, 1.4 mm, 1.5 mm, etc.

[0059] In some embodiments, the thickness of the bottom protective plate is 1.5mm to 5.0mm, such as 1.5mm, 2.0mm, 2.5mm, 3.0mm, 3.5mm, 4.0mm, 4.5mm, 5.0mm, etc. The thickness of the bottom protective plate 1 is within the above range, which can effectively protect the battery pack while reducing the weight of the bottom protective plate itself.

[0060] Secondly, this utility model provides a vehicle that includes a battery pack 2 and a bottom protection plate. The bottom protection plate is the bottom protection plate 1 described in the first aspect, and the upper fiber-reinforced resin layer 11 of the bottom protection plate 1 is opposite to the battery pack 2.

[0061] Because of the underbody protection plate described in the first aspect, the vehicle of this utility model embodiment has all the advantages brought by the underbody protection plate described in the first aspect, which will not be repeated here.

[0062] The present invention will now be described in detail with reference to the embodiments and accompanying drawings.

[0063] Specific experimental methods are not specified in the following examples; they are generally performed under standard conditions or as recommended by the manufacturer. Unless otherwise stated, all percentages and parts are by weight.

[0064] Example 1 In this embodiment, the bottom protective plate 1 has a three-layer structure, consisting of an upper fiber-reinforced resin layer 11, a rigid body layer 12, and a lower fiber-reinforced resin layer 13, which are sequentially stacked from the direction closest to the battery pack 2 to the direction furthest from the battery pack 2. The upper fiber-reinforced resin layer 11 and the lower fiber-reinforced resin layer 13 satisfy the following condition: d 上 / d 下 =0.1, where d 上The thickness of the upper fiber-reinforced resin layer is expressed in mm, d. 下 The thickness of the lower fiber-reinforced resin layer is expressed in mm.

[0065] The total mass of the fiber-reinforced resin layer 11 is 100 wt.%, with a glass fiber content of 66 wt.% and a polyurethane resin content of 34 wt.%. The elastic modulus of the upper fiber-reinforced resin layer 11 in the 0˚ direction (i.e., in the thickness direction of the bottom protective plate, or in other words, in the direction perpendicular to the surface of the bottom protective plate) is 23 GPa. The density of the upper fiber-reinforced resin layer 11 is 1.9 g / cm³. 3 The thickness d of the upper fiber-reinforced resin layer 11 上 It is 0.18mm.

[0066] The rigid layer 12 is a steel plate; the flexural modulus of the rigid layer 12 in the 0˚ direction (i.e., in the thickness direction of the bottom protective plate, or in the direction perpendicular to the surface of the bottom protective plate) is 200 GPa; the thickness of the rigid layer 12 is 0.8 mm.

[0067] The lower fiber-reinforced resin layer 13, based on a total mass of 100 wt.%, contains 66 wt.% glass fiber and 34 wt.% polyurethane resin; the elastic modulus of the lower fiber-reinforced resin layer 13 in the 0˚ direction (i.e., in the thickness direction of the bottom protective plate, or in other words, in the direction perpendicular to the surface of the bottom protective plate) is 23 GPa; the density of the lower fiber-reinforced resin layer 13 is 1.9 g / cm³. 3 The thickness d of the lower fiber-reinforced resin layer 11 下 It is 1.82mm.

[0068] The total thickness of the bottom guard plate 1 is 2.8mm.

[0069] The method for preparing the bottom protective plate in this embodiment includes the following steps: 1. Analyze the product's digital model and output the material cutting diagram.

[0070] Provide fiberglass cloth (EBT650, Jiangsu Jiuding Industrial Materials Co., Ltd.); then use automatic cutting equipment to cut the fiberglass cloth.

[0071] In addition, the steel plate is pretreated by sandblasting, shot blasting, degreasing and dust removal to obtain the pretreated steel plate.

[0072] In addition, isocyanate components and isocyanate reactive components are provided: Polymerized MDI (NCO content 31.2 wt.%, Wanhua Chemical), WANNATEMDI-100 (NCO content 33.5 wt.%, Wanhua Chemical), and diethylene glycol modified MDI (NCO content 21.0 wt.%, Wanhua Chemical) were weighed in a mass ratio of 20:30:50 and mechanically stirred at 2000 rpm for 30 min at 25 °C to prepare the isocyanate component.

[0073] Weigh out polytetrahydrofuran polyol (brand name: PTMEG2000, weight average molecular weight 2200, hydroxyl value 50mgKOH / g, Hyosung Chemical), polyether polyol (brand name: F3156, weight average molecular weight 3000, glycerol initiator, hydroxyl value 57mgKOH / g, Wanhua Chemical), chain extender ethylene glycol, and flame retardant tri(chloroisopropyl) phosphate (TCPP) in a mass ratio of 40:10:30:20. Mix the materials uniformly at 5000 rpm under mechanical stirring at 25°C to obtain the isocyanate reactive component.

[0074] 2. Place the pretreated steel plate on top of the cut fiberglass cloth, transfer both to the preforming mold simultaneously, and fix them together with adhesive to obtain the preform.

[0075] 3. Provide a dedicated mold for the high-pressure resin transfer molding (HP-RTM) process, clean the HP-RTM mold, spray a release agent on the surface of the HP-RTM mold, transfer the preform into the HP-RTM mold, install bolts and tighten the HP-RTM mold, then evacuate the HP-RTM mold, preheat the HP-RTM mold to 120°C and lock the mold, control the vacuum degree of the mold cavity to -0.98 Bar, and inject the isocyanate component and isocyanate reactive component into both sides of the preform in the HP-RTM mold through a high-pressure injection gun at a mass ratio of 1:1.2. The injection pressure is 10 MPa. After injection, hold the pressure for 3 minutes for hot pressing molding, and then open the mold to obtain the bottom protection plate of this embodiment.

[0076] The isocyanate component and the isocyanate reactive component react to form a polyurethane resin (tensile strength of 28 MPa, elongation at break of 110%, tear strength of 17 kN / m). The polyurethane resin and the glass fiber cloth together form the upper fiber-reinforced resin layer 11 and the lower fiber-reinforced resin layer 13.

[0077] Post-processing: Using cutting equipment, the waste edges of the bottom protective plate in this embodiment are removed according to the bottom protective plate drawing requirements, and holes are made in the bottom protective plate in this embodiment.

[0078] Example 2 The bottom protective plate in this embodiment is the same as that in Embodiment 1, the only difference being that d上 / d 下 =0.2, the thickness of the upper fiber-reinforced resin layer 11 is 0.33mm and the thickness of the lower fiber-reinforced resin layer 13 is 1.67mm, and the total thickness of the bottom protective plate 1 is 2.8mm.

[0079] Example 3 The bottom protective plate in this embodiment is the same as that in Embodiment 1, the only difference being that d 上 / d 下 =0.25, the thickness of the upper fiber-reinforced resin layer 11 is 0.4mm and the thickness of the lower fiber-reinforced resin layer 13 is 1.6mm, and the total thickness of the bottom protective plate 1 is 2.8mm.

[0080] Example 4 The bottom protective plate in this embodiment is the same as that in Embodiment 1, the only difference being that d 上 / d 下 =0.3, the thickness of the upper fiber-reinforced resin layer 11 is 0.46mm and the thickness of the lower fiber-reinforced resin layer 13 is 1.54mm, and the total thickness of the bottom protective plate 1 is 2.8mm.

[0081] Example 5 The bottom protective plate in this embodiment is the same as that in Embodiment 1, the only difference being that d 上 / d 下 =0.35, the thickness of the upper fiber-reinforced resin layer 11 is 0.52mm and the thickness of the lower fiber-reinforced resin layer 13 is 1.48mm, and the total thickness of the bottom protective plate 1 is 2.8mm.

[0082] Comparative Example 1 The bottom protective plate in this comparative example is the same as that in Example 1, except that d 上 / d 下 =0.4, the thickness of the upper fiber-reinforced resin layer 11 is 0.57mm and the thickness of the lower fiber-reinforced resin layer 13 is 1.43mm, and the total thickness of the bottom protective plate 1 is 2.8mm.

[0083] Comparative Example 2 The bottom protective plate in this comparative example is the same as that in Example 1, except that d 上 / d 下 =0.5, the thickness of the upper fiber-reinforced resin layer 11 is 0.67mm and the thickness of the lower fiber-reinforced resin layer 13 is 1.33mm, and the total thickness of the bottom protective plate 1 is 2.8mm.

[0084] Performance testing: (1) The tensile strength of the polyurethane resin was tested. The standard for tensile strength testing is GB / T528-2009.

[0085] (2) The elongation at break of polyurethane resin was tested. The standard for elongation at break test is GB / T528-2009.

[0086] (3) The tear strength test of polyurethane resin is performed. The tear strength test standard is GB / T529.

[0087] (4) The elastic modulus of the upper fiber-reinforced resin layer and the lower fiber-reinforced resin layer were tested respectively. The standard for elastic modulus testing is GB / T528-2009.

[0088] (5) The steel plate is subjected to bending modulus test. The bending modulus test standard is GB / T9341-2008.

[0089] (6) Drop ball impact tests were conducted on the bottom protective plates prepared in the above embodiments and comparative examples. The drop ball impact tests were carried out using a self-made drop ball device. The ball was magnetically pulled up to a certain height and then dropped vertically onto the surface of the bottom protective plate sample. The deformation at the point of impact on the bottom protective plate sample was then measured. The diameter of the ball head was 25 mm, the length of the ball head was 50 mm, and the total weight of the ball was 60 kg. The actual area of ​​the bottom protective plate sample was 360 mm * 360 mm, and the effective area of ​​the bottom protective plate sample after locking was 300 mm * 300 mm. In the 500 J impact test, the ball was pulled up to a height of 0.85 m, and in the 600 J impact test, the ball was pulled up to a height of 1.02 m.

[0090] Table 1. Key parameters and performance test results of the bottom protective plates obtained in Examples 1-5 above.

[0091] Table 2. Key parameters and performance test results of the bottom protection plates obtained in Comparative Examples 1 and 2 above.

[0092] In this utility model, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0093] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A bottom protective plate, characterized in that, The bottom protective plate includes an upper fiber-reinforced resin layer, a rigid body layer, and a lower fiber-reinforced resin layer. The rigid body layer is located between the upper fiber-reinforced resin layer and the lower fiber-reinforced resin layer, and the upper fiber-reinforced resin layer and the lower fiber-reinforced resin layer satisfy the following condition: 0.1 ≤ d 上 / d 下 <0.4, d 下 The thickness is 1.8mm to 2.0mm, where d 上 The thickness of the upper fiber-reinforced resin layer is expressed in mm, d. 下 The thickness of the lower fiber-reinforced resin layer is in mm; the upper fiber-reinforced resin layer is at least one of fiber-reinforced polyurethane resin layer, fiber-reinforced epoxy resin layer, fiber-reinforced vinyl resin layer, fiber-reinforced polyurethane-modified epoxy resin layer, fiber-reinforced polyurethane-modified vinyl resin layer, and fiber-reinforced epoxy-modified vinyl resin layer; and / or, the upper fiber-reinforced resin layer is at 0... The elastic modulus in the axial direction is 0.5 GPa to 30 GPa; and / or, the density of the upper fiber-reinforced resin layer is 1.5 g / cm³. 3 ~2.1g / cm 3 .

2. The bottom protective plate according to claim 1, characterized in that, The upper fiber-reinforced resin layer and the lower fiber-reinforced resin layer satisfy the following condition: 0.3 ≤ d 上 / d 下 <0.

4.

3. The bottom protective plate according to claim 1, characterized in that, The thickness d of the upper fiber-reinforced resin layer 上 The thickness ranges from 0.2mm to 0.7mm.

4. The bottom protective plate according to claim 3, characterized in that, The thickness d of the upper fiber-reinforced resin layer 上 The thickness is 0.5mm to 0.7mm.

5. The bottom protective plate according to any one of claims 1 to 4, characterized in that, The lower fiber-reinforced resin layer includes at least one of fiber-reinforced polyurethane resin layer, fiber-reinforced epoxy resin layer, fiber-reinforced vinyl resin layer, fiber-reinforced polyurethane-modified epoxy resin layer, fiber-reinforced polyurethane-modified vinyl resin layer, and fiber-reinforced epoxy-modified vinyl resin layer. And / or, the lower fiber-reinforced resin layer is at 0 The elastic modulus in the directional direction is 0.5 GPa to 30 GPa; And / or, the density of the lower fiber-reinforced resin layer is 1.5 g / cm³. 3 ~2.1g / cm 3 .

6. The bottom protective plate according to any one of claims 1 to 4, characterized in that, The rigid layer is at 0 Flexural modulus in the direction of flexural elasticity ≥ 80 GPa; And / or, the rigid layer includes at least one of a metal plate, a plastic plate, and a high-rigidity composite plate; And / or, the thickness of the rigid body layer is 0.4 mm to 1.5 mm.

7. The bottom protective plate according to any one of claims 1 to 4, characterized in that, The thickness of the bottom protective plate is 1.5mm to 5.0mm.

8. A vehicle, characterized in that, The vehicle includes a battery pack and a bottom protection plate, wherein the bottom protection plate is the bottom protection plate according to any one of claims 1 to 7, and the upper fiber-reinforced resin layer of the bottom protection plate is opposite to the battery pack.

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