Bottom guard plate

Abstract

The utility model discloses a bottom protection plate which comprises a first surface layer, a honeycomb layer, a metal layer and a second surface layer which are arranged in a stacked mode. The first surface layer comprises a plurality of first glass fiber layers with laying angles of a first angle and a second angle, and the number of the first glass fiber layers laid at the first angle is larger than that of the second glass fiber layers laid at the second angle; the second surface layer comprises a plurality of second glass fiber layers which are laid at third angles and fourth angles, and the number of the second glass fiber layers laid at the third angles is larger than that of the second glass fiber layers laid at the fourth angles. Thus, when the bottom protection plate is installed on the vehicle, the extension direction of the first glass fiber layer with the laying angle being the first angle and the extension direction of the second glass fiber layer with the laying angle being the third angle are the same as the length direction of the vehicle, the strength and rigidity of the bottom protection plate in the length direction of the vehicle are enhanced, and the bottom protection plate can bear longitudinal impact and vibration encountered by the vehicle; the first glass fiber layer with the first angle and the second glass fiber layer with the third angle disperse impact and stress in different directions, and durability and reliability of the bottom protection plate are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of bottom guard plates, in particular to a bottom guard plate. Background Art

[0002] The power battery pack of new energy vehicles is generally placed on a tray on the vehicle chassis. In order to prevent the battery from being damaged by external forces, a bottom guard plate needs to be added to the bottom of the tray.

[0003] In the prior art, the bottom guard plate adopts upper and lower layers of continuous glass fiber reinforced thermoplastic composite materials. However, in this structure, the upper and lower layers usually adopt thicker single-layer CFRT (glass fiber polyethylene composite material), which has weak impact resistance. When subjected to external force, stress will be concentrated in certain areas, causing premature failure of materials in certain areas, thereby reducing the bearing capacity and service life of the entire bottom guard plate. Utility Model Content

[0004] In order to solve the above technical problems, the utility model provides a bottom guard plate.

[0005] The utility model provides a bottom guard plate, comprising a first surface layer, a honeycomb layer, a metal layer and a second surface layer which are stacked in sequence;

[0006] The first surface layer includes multiple stacked first glass fiber layers, a portion of the first glass fiber layers are laid at a first angle, another portion of the first glass fiber layers are laid at a second angle, and the number of the first glass fiber layers laid at the first angle is greater than the number of the first glass fiber layers laid at the second angle;

[0007] The second surface layer includes a plurality of stacked second glass fiber layers, wherein a portion of the second glass fiber layers are laid at a third angle, and another portion of the second glass fiber layers are laid at a fourth angle, and the number of the second glass fiber layers laid at the third angle is greater than the number of the second glass fiber layers laid at the fourth angle;

[0008] The angle difference between the first angle and the third angle is smaller than the angle difference between the first angle and the fourth angle, and the angle difference between the second angle and the fourth angle is smaller than the angle difference between the second angle and the third angle.

[0009] In some embodiments of the present disclosure, the first angle is 0°, the second angle is 90°, the third angle is 0°, and the fourth angle is 90°.

[0010] In some embodiments of the present disclosure, the thickness of a single layer of the first glass fiber layer and a single layer of the second glass fiber layer are both 0.1-0.15 mm.

[0011] In some embodiments of the present disclosure, the first glass fiber layer has 8 layers, and the laying angles of the first glass fiber layer are 90°, 0°, 0°, 0°, 0°, 0°, 0°, 90° in sequence;

[0012] Or, the laying angles of the first glass fiber layer are 0°, 0°, 90°, 0°, 0°, 90°, 0°, 0°, and 0°, respectively.

[0013] In some embodiments of the present disclosure, the first glass fiber layer includes 9 layers, and the laying angles of the first glass fiber layer are 90°, 0°, 0°, 0°, 90°, 0°, 0°, 0°, and 90°, respectively.

[0014] In some embodiments of the present disclosure, the second glass fiber layer has 8 layers, and the laying angles of the second glass fiber layer are 90°, 0°, 0°, 0°, 0°, 0°, 0°, 90° in sequence;

[0015] Or, the laying angles of the second glass fiber layer are 0°, 0°, 90°, 0°, 0°, 90°, 0°, 0°, and 0°, respectively.

[0016] In some embodiments of the present disclosure, the second glass fiber layers include 9 layers, and the laying angles of the second glass fiber layers are 90°, 0°, 0°, 0°, 90°, 0°, 0°, 0°, 90°.

[0017] In some embodiments of the present disclosure, the first glass fiber layer is a glass fiber polyethylene composite material layer; and the second glass fiber layer is a glass fiber polyethylene composite material layer.

[0018] In some embodiments of the present disclosure, the metal layer includes a steel plate.

[0019] In some embodiments of the present disclosure, an identification structure is provided on the first surface layer, and the first surface layer is used to be installed on a side close to the battery pack.

[0020] The bottom guard plate provided by the utility model has at least the following advantages:

[0021] The bottom guard plate provided by the utility model has multiple first glass fiber layers with different laying angles laid in the first surface layer, and multiple second glass fiber layers with different laying angles arranged in the second surface layer. The laying at different angles helps to improve the anti-twisting performance of the bottom guard plate, so that the bottom guard plate can maintain good stability when subjected to forces from different directions, and the number of first glass fiber layers laid at the first angle is more than that at the second angle, and the number of second glass fiber layers laid at the third angle is more than that at the fourth angle. In this way, when the bottom guard plate is installed on the vehicle, the extension directions of the first glass fiber layers with the laying angle of the first angle and the second glass fiber layers with the laying angle of the third angle in the bottom guard plate can be made to be roughly the same as the length direction of the vehicle, which can enhance the strength and rigidity of the bottom guard plate in the length direction of the vehicle, and help the bottom guard plate to better withstand the longitudinal impact and vibration that the vehicle may encounter during driving. The first glass fiber layers at the first angle and the second glass fiber layers at the third angle disperse and absorb the impact and stress from different directions, thereby improving the durability and reliability of the bottom guard plate, making the force more uniform, and reducing the stress concentration phenomenon. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 A schematic diagram of the cross-sectional structure of a bottom guard plate provided for an exemplary embodiment of the utility model.

[0024] The following are marked in the accompanying drawings:

[0025] 1. First surface layer; 2. Honeycomb layer; 3. Metal layer; 4. Second surface layer. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative work are within the protection scope of the utility model.

[0027] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0028] The power battery pack of new energy vehicles is generally placed on a tray on the vehicle chassis. In order to prevent the battery from being damaged by external forces, a bottom guard plate needs to be added to the bottom of the tray.

[0029] In the prior art, the bottom guard plate adopts upper and lower layers of continuous glass fiber reinforced thermoplastic composite materials. However, in this structure, the upper and lower layers usually adopt thicker single-layer CFRT (glass fiber polyethylene composite material), which has weak impact resistance. When subjected to external force, stress will be concentrated in certain areas, causing premature failure of materials in certain areas, thereby reducing the bearing capacity and service life of the entire bottom guard plate.

[0030] Combine the following Figure 1 The embodiments of the present utility model are further described.

[0031] In order to solve the above technical problems, the utility model provides a bottom guard plate, which helps to improve the anti-twisting performance of the bottom guard plate by laying multiple first glass fiber layers with different laying angles in the first surface layer and arranging multiple second glass fiber layers with different laying angles in the second surface layer, and laying them at different angles, so that the bottom guard plate can maintain good stability when subjected to forces from different directions, and the number of first glass fiber layers laid at the first angle is more than that at the second angle, and the number of second glass fiber layers laid at the third angle is more than that at the fourth angle. In this way, when the bottom guard plate is installed on the vehicle, the extension directions of the first glass fiber layer with the laying angle of the first angle and the second glass fiber layer with the laying angle of the third angle in the bottom guard plate can be made to be roughly the same as the length direction of the vehicle, which can enhance the strength and rigidity of the bottom guard plate in the length direction of the vehicle, and help the bottom guard plate better withstand the longitudinal impact and vibration that the vehicle may encounter during driving. The first glass fiber layer at the first angle and the second glass fiber layer at the third angle disperse and absorb the impact and stress from different directions, thereby improving the durability and reliability of the bottom guard plate, making the force more uniform, and reducing the stress concentration phenomenon.

[0032] An exemplary embodiment of the present disclosure provides an underbody guard plate, which is installed on a car, wherein the car can be a new energy car or a fuel car. When the car is a new energy car, the underbody guard plate can be used as an underbody guard plate of a motor of a new energy car, or as an underbody guard plate of a battery of a new energy car; when the car is a fuel car, the underbody guard plate can be used as an underbody guard plate of an engine of a fuel car.

[0033] like Figure 1 As shown, it includes a first surface layer 1, a honeycomb layer 2, a metal layer 3 and a second surface layer 4 which are stacked in sequence. When the layers are stacked, the honeycomb layer 2 is used as the center, and each layer is stacked with a film to obtain a composite layer.

[0034] The first surface layer 1 includes multiple stacked first glass fiber layers, wherein a portion of the first glass fiber layers is laid at a first angle, another portion of the first glass fiber layers is laid at a second angle, and the number of first glass fiber layers laid at the first angle is greater than the number of first glass fiber layers laid at the second angle; the second surface layer 4 includes multiple stacked second glass fiber layers, wherein a portion of the second glass fiber layers is laid at a third angle, another portion of the second glass fiber layers is laid at a fourth angle, and the number of second glass fiber layers laid at the third angle is greater than the number of second glass fiber layers laid at the fourth angle; wherein the angle difference between the first angle and the third angle is smaller than the angle difference between the first angle and the fourth angle, and the angle difference between the second angle and the fourth angle is smaller than the angle difference between the second angle and the third angle,

[0035] Exemplarily, the angle difference between the first angle and the third angle can be 0, the angle difference between the first angle and the fourth angle can be 90 or 45, the angle difference between the second angle and the fourth angle can be 0, and the angle difference between the second angle and the third angle can be 90 or 45. In other words, the first angle is substantially the same as the third angle, and the second angle is substantially the same as the fourth angle. It should be noted that the number of plies of the first glass fiber layer in the first surface layer 1 can be the same as the number of plies of the second glass fiber layer in the second surface layer 4, and the number of plies of the first glass fiber layer in the first surface layer 1 can be different from the number of plies of the second glass fiber layer in the second surface layer 4. For example, 8 layers of the first glass fiber layer are laid in the first surface layer 1, and 9 layers of the second glass fiber layer are laid in the second surface layer 4, wherein the laying angle of the first glass fiber layer can be the same as or different from the laying angle of the second glass fiber layer.

[0036] The first surface layer 1 is a first glass fiber layer laminated by multiple layers through melting and hot pressing, and the second surface layer 4 is a second glass fiber layer laminated by multiple layers through melting and hot pressing. Glass fiber is used to make the first glass fiber layer and the second glass fiber layer have the characteristics of light weight and high mechanical properties. Among them, the laying angle of a part of the first glass fiber layer is the first angle, the laying angle of another part of the first glass fiber layer is the second angle, and the number of the first glass fiber layer laid at the first angle is greater than the number of the first glass fiber layer laid at the second angle, the laying angle of a part of the second glass fiber layer is the third angle, and the laying angle of another part of the second glass fiber layer is the fourth angle, and the number of the second glass fiber layer laid at the third angle is greater than the number of the second glass fiber layer laid at the fourth angle. In this way, laying at different angles helps to improve the anti-twisting performance of the bottom guard plate, so that the bottom guard plate can maintain good stability when subjected to forces from different directions, so that the stack can disperse the force when subjected to force, avoid excessive local force, and pierce the board layer, so that the bottom guard plate can withstand greater external force and impact. At the same time, the number of first glass fiber layers laid at the first angle is greater than that of first glass fiber layers laid at the second angle, and the number of second glass fiber layers laid at the third angle is greater than that of second glass fiber layers laid at the fourth angle. This difference in quantity can optimize the force distribution of the bottom guard plate. When the bottom guard plate is installed on the vehicle, the extension direction of the first glass fiber layer laid at the first angle and the second glass fiber layer laid at the third angle in the bottom guard plate can be made to be roughly the same as the length direction of the vehicle, which can enhance the strength and rigidity of the bottom guard plate in the length direction of the vehicle, and help the bottom guard plate to better withstand the longitudinal impact and vibration that the vehicle may encounter during driving. The first glass fiber layer at the first angle and the second glass fiber layer at the third angle disperse and absorb impacts and stresses from different directions, thereby improving the durability and reliability of the bottom guard plate, making the bottom guard plate more evenly stressed when subjected to external force, thereby reducing stress concentration.

[0037] In some embodiments of the present invention, referring to Figure 1, the first angle is 0°, the second angle is 90°, the third angle is 0°, and the fourth angle is 90°. In this way, the 0° first glass fiber layer laid in the first surface layer 1 is more than the 90° first glass fiber layer, and the 0° second glass fiber layer laid in the second surface layer 4 is more than the 90° second glass fiber layer, which is beneficial for more surfaces to bear and dissipate external forces, and can provide more strength support, so that when the bottom guard plate is subjected to external forces, the force is more uniform, reducing the stress concentration phenomenon. It should be noted that the 0° first glass fiber layer means that the laying angle of the first glass fiber layer is 0°, the 90° first glass fiber layer means that the laying angle of the first glass fiber layer is 90°, the 0° second glass fiber layer means that the laying angle of the second glass fiber layer is 0°, and the 90° second glass fiber layer means that the laying angle of the second glass fiber layer is 90°.

[0038] In some embodiments of the present invention, referring to Figure 1 , the thickness of the single-layer first glass fiber layer and the single-layer second glass fiber layer are both 0.1-0.15mm. Exemplarily, the thickness of the single-layer first glass fiber layer and the single-layer second glass fiber layer are both 0.1mm. In this way, with the same thickness of the first surface layer 1 and the second surface layer 4, more layers can be laid in different directions to provide more strength support for the bottom guard plate, thereby improving the durability and service life of the bottom guard plate.

[0039] In some embodiments of the present invention, referring to Figure 1 , the first glass fiber layer is 8 layers, and the laying angles of the first glass fiber layer are 90°, 0°, 0°, 0°, 0°, 0°, 0°, and 90° in sequence. Figure 1 , the first glass fiber layer is 8 layers, and the laying angles of the first glass fiber layer are 0°, 0°, 90°, 0°, 0°, 90°, 0°, 0°. In this way, by alternately laying the first glass fiber layers of 90° and 0°, and the number of the laid 0° first glass fiber layers is greater than the number of the 90° first glass fiber layers, the 0° first glass fiber layer is beneficial for more surfaces to bear and dissipate external forces, and can provide more strength to support the bottom guard plate to achieve a balanced force distribution in different directions, which helps to reduce stress concentration and improve the overall force performance of the bottom guard plate, so that the thickness of the first surface layer 1 is more uniform, and the overall structural strength of the bottom guard plate is improved. The 8 first glass fiber layers can cooperate with each other to jointly bear and disperse external loads, and improve the impact resistance and extrusion resistance of the bottom guard plate.

[0040] In some embodiments of the present invention, referring to 4, the first glass fiber layer is 9 layers, and the laying angles of the first glass fiber layer are 90°, 0°, 0°, 0°, 90°, 0°, 0°, 0°, 90°. In this way, 9 layers of the first glass fiber layer are provided, the thickness and fiber quantity of the first surface layer 1 are increased, thereby improving the stability and bearing capacity of the bottom guard plate. The number of plies of the 0° first glass fiber layer is greater than the number of plies of the 90° first glass fiber layer. The 0° first glass fiber layer is beneficial for bearing and dissipating external forces. More surfaces can more effectively disperse and resist external forces, and reduce stress concentration and deformation.

[0041] In some embodiments of the present invention, referring to Figure 1 , the second glass fiber layer is 8 layers, and the laying angles of the second glass fiber layer are 90°, 0°, 0°, 0°, 0°, 0°, 0°, and 90° in sequence. Figure 1 , the second glass fiber layer is 8 layers, and the laying angles of the second glass fiber layer are 0°, 0°, 90°, 0°, 0°, 90°, 0°, 0°, respectively. Among them, the number of plies of the first glass fiber layer in the first surface layer 1 can be the same as or different from the number of plies of the second glass fiber layer in the second surface layer 4, and the laying angles of the plies of the first glass fiber layer can be the same as or different from the laying angles of the plies of the second glass fiber layer. It can be understood that, for example, when the second glass fiber layer has 8 layers and the laying angles of the second glass fiber layer are 90°, 0°, 0°, 0°, 0°, 0°, 0°, 90° in sequence, the first glass fiber layer can be 8 layers or 9 layers, and the laying angles of the first glass fiber layer can be 90°, 0°, 0°, 0°, 0°, 0°, 90° in sequence, or 0°, 0°, 90°, 0°, 90°, 0°, 0°, 90°, 0°, 0°, or 90°, 0°, 0°, 0°, 90°, 0°, 0°, 0°, 90°, 0°, 0°, 90°.

[0042] In this way, by alternately laying the second glass fiber layers at 90° and 0°, and the number of the laid 0° second glass fiber layers is greater than the number of the 90° second glass fiber layers, the 0° second glass fiber layers are beneficial for more surfaces to bear and dissipate external forces, and can provide more strength to support the bottom guard plate to achieve a balanced force distribution in different directions, which helps to reduce stress concentration and improve the overall force-bearing performance of the bottom guard plate, making the thickness of the second surface layer 4 more uniform, and the overall structural strength of the bottom guard plate is improved. The 8 second glass fiber layers can cooperate with each other to jointly bear and disperse external loads, thereby improving the impact resistance and extrusion resistance of the bottom guard plate.

[0043] In some embodiments of the present invention, referring to Figure 1, the second glass fiber layer is 9 layers, and the laying angles of the second glass fiber layer are 90°, 0°, 0°, 0°, 90°, 0°, 0°, 0°, 90°. In this way, 9 layers of the second glass fiber layer are provided, the thickness and fiber quantity of the second surface layer 4 are increased, thereby improving the stability and bearing capacity of the bottom guard plate. The number of plies of the 0° second glass fiber layer is greater than the number of plies of the 90° second glass fiber layer. The 0° second glass fiber layer is beneficial for bearing and dissipating external forces. More surfaces can more effectively disperse and resist external forces, and reduce stress concentration and deformation.

[0044] In some embodiments of the present invention, referring to Figure 1 , the first glass fiber layer is a glass fiber polyethylene composite material layer; the second glass fiber layer is a glass fiber polyethylene composite material layer. In this way, the glass fiber polyethylene composite material layer combines the high strength and high modulus of glass fiber with the toughness of polyethylene, so that the bottom guard plate has better resistance to impact and extrusion, and can better disperse and withstand stress when subjected to external forces, thereby improving the overall strength of the bottom guard plate, which enables the bottom guard plate to operate stably for a long time in various harsh environments. At the same time, the glass fiber polyethylene composite material has the characteristics of light weight and high strength. Compared with traditional metal materials, it can reduce the weight of the bottom guard plate while ensuring strength, which helps to reduce the overall weight of the vehicle, improve fuel economy, and reduce the impact on the environment.

[0045] In some embodiments of the present invention, referring to Figure 1 The metal layer 3 includes a steel plate. The steel plate of the metal layer 3 can be a DP780 steel plate. In this way, the steel plate has high mechanical properties, has the strength provided by the metal layer 3, but is not too heavy. It has high strength and light weight, and achieves a good balance between the mechanical properties and weight of the product. It can effectively support and protect the bottom guard plate and key components of the bottom of the vehicle. In the event of a collision or impact, the steel plate can effectively reduce damage, protect the structural integrity and normal function of the vehicle, and enhance the stability of the bottom guard plate.

[0046] In some embodiments of the present invention, referring to Figure 1 , an identification structure is provided on the first surface layer 1, and the first surface layer 1 is used to be installed on the side close to the battery pack. In this way, by providing the identification structure on the first surface layer 1, the bottom guard plate is easier to identify and locate during installation and use, which can help the staff to quickly and accurately find the bottom guard plate and its installation position, improve the installation efficiency and accuracy, and at the same time, through the identification structure, the specifications, model, production date and other important information of the bottom guard plate can be clearly identified, which is conducive to the subsequent maintenance and management of the vehicle by the staff.

[0047] The contents described above can be implemented individually or in combination in various ways, and these variations are all within the protection scope of the present utility model.

[0048] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device comprising the elements.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model is described in detail with reference to the above embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the above embodiments, or replace some of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the utility model.

Claims

1. A bottom guard plate, characterized in that: It comprises a first surface layer, a honeycomb layer, a metal layer and a second surface layer which are stacked in sequence; The first surface layer includes multiple stacked first glass fiber layers, a portion of the first glass fiber layers are laid at a first angle, another portion of the first glass fiber layers are laid at a second angle, and the number of the first glass fiber layers laid at the first angle is greater than the number of the first glass fiber layers laid at the second angle; The second surface layer includes a plurality of stacked second glass fiber layers, wherein a portion of the second glass fiber layers are laid at a third angle, and another portion of the second glass fiber layers are laid at a fourth angle, and the number of the second glass fiber layers laid at the third angle is greater than the number of the second glass fiber layers laid at the fourth angle; The angle difference between the first angle and the third angle is smaller than the angle difference between the first angle and the fourth angle, and the angle difference between the second angle and the fourth angle is smaller than the angle difference between the second angle and the third angle.

2. The bottom guard plate according to claim 1, characterized in that: The first angle is 0°, the second angle is 90°, the third angle is 0°, and the fourth angle is 90°.

3. The bottom guard plate according to claim 2, characterized in that: The thickness of the single-layer first glass fiber layer and the single-layer second glass fiber layer are both 0.1-0.15 mm.

4. The bottom guard plate according to claim 3, characterized in that: The first glass fiber layers include 8 layers, and the laying angles of the first glass fiber layers are 90°, 0°, 0°, 0°, 0°, 0°, 0°, and 90° in sequence; Or, the laying angles of the first glass fiber layer are 0°, 0°, 90°, 0°, 0°, 90°, 0°, 0°, and 0°, respectively.

5. The bottom guard plate according to claim 3, characterized in that: The first glass fiber layers include 9 layers, and the laying angles of the first glass fiber layers are 90°, 0°, 0°, 0°, 90°, 0°, 0°, 0°, and 90°, respectively.

6. The bottom guard plate according to claim 3, characterized in that: The second glass fiber layers include 8 layers, and the laying angles of the second glass fiber layers are 90°, 0°, 0°, 0°, 0°, 0°, 0°, and 90° in sequence; Or, the laying angles of the second glass fiber layer are 0°, 0°, 90°, 0°, 0°, 90°, 0°, 0°, and 0°, respectively.

7. The bottom guard plate according to claim 3, characterized in that: The second glass fiber layers include 9 layers, and the laying angles of the second glass fiber layers are 90°, 0°, 0°, 0°, 90°, 0°, 0°, 0°, and 90°.

8. The bottom guard plate according to claim 1, characterized in that: The first glass fiber layer is a glass fiber polyethylene composite material layer; The second glass fiber layer is a glass fiber polyethylene composite material layer.

9. The bottom guard plate according to claim 1, characterized in that: The metal layer includes a steel plate.

10. The bottom guard plate according to claim 1, characterized in that: The first surface layer is provided with a marking structure, and the first surface layer is used for installation on a side close to the battery pack.

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