CN117199668A - Battery protection bottom plate, battery package composite protection structure and vehicle - Google Patents

Abstract

The invention provides a battery protection bottom plate, which comprises an upper fiber reinforced resin layer, a metal plate, a fiber reinforced resin frame and a lower fiber reinforced resin layer, wherein the metal plate and the fiber reinforced resin frame are positioned on the upper fiber reinforced resin layer and the lower fiber reinforced resin layerThe battery protection bottom plate comprises a lower fiber reinforced resin layer, wherein the lower fiber reinforced resin layer is a frame body structure formed by connecting a plurality of frame plates end to end, the metal plate is positioned inside the fiber reinforced resin frame, a plurality of mounting holes are formed in the inner side of the edge of the battery protection bottom plate at intervals, and the battery protection bottom plate meets the following conditions: 0.4 < D +.lg (D) ₀ *W/L)/L ₂ And is less than or equal to 2. Meanwhile, the invention also discloses a battery pack composite protection structure comprising the battery protection bottom plate and a vehicle. The battery protection bottom plate provided by the invention is beneficial to avoiding the problem that the connecting piece is loosened and layered under the working condition of long-term vibration.

Description

Battery protection bottom plate, battery pack composite protection structure and vehicle

Technical Field

The present invention belongs to the technical field of vehicle batteries, and in particular relates to a battery protection bottom plate, a battery pack composite protection structure and a vehicle.

Background Art

With the rapid development of electric vehicles, people have higher and higher safety requirements for electric vehicles. As the power source of electric vehicles, the safety of power battery packs is of great importance. In electric vehicles, the battery pack is generally located at the bottom of the vehicle chassis and connected to the chassis by bolts. The lower surface of the battery pack is exposed. During daily driving of the vehicle, the bottom of the battery pack is prone to collision, causing the box to rupture and the protection to fail. Stone splashing from the bottom during driving can also cause impact on the battery pack. In order to cope with complex working conditions, a protective plate is usually provided at the bottom of the battery pack to protect the bottom of the battery pack. At the same time, vibration is inevitable during the driving of the vehicle. Under the action of long-term vibration and impact, the existing protective plates are prone to loosening of the connecting rivets or falling off of the surface protective layer.

Summary of the invention

In view of the problem that rivets on existing battery pack protection plates are loose or the surface protection layer falls off, the present invention provides a battery protection bottom plate, a battery pack composite protection structure and a vehicle.

The technical solution adopted by the present invention to solve the above technical problems is as follows:

On the one hand, the present invention provides a battery protection bottom plate, comprising an upper fiber reinforced resin layer, a metal plate, a fiber reinforced resin frame and a lower fiber reinforced resin layer, wherein the metal plate and the fiber reinforced resin frame are located between the upper fiber reinforced resin layer and the lower fiber reinforced resin layer, wherein the fiber reinforced resin frame is a frame structure formed by connecting a plurality of frame plates end to end, wherein the metal plate is located inside the fiber reinforced resin frame, wherein the top surface of the fiber reinforced resin frame is integrally connected to the upper fiber reinforced resin layer, and the bottom surface of the fiber reinforced resin frame is integrally connected to the lower fiber reinforced resin layer; wherein a plurality of mounting holes are spaced apart on the inner side of the edge of the battery protection bottom plate, wherein the mounting holes sequentially pass through the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer, and wherein the battery protection bottom plate satisfies the following conditions:

0.4≤-D*lg(d ₀ *W/L)/L ₂ ≤2

Where D is the diameter of the mounting hole, in mm;

_d0 is the total thickness of the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer, in mm;

W is the width of the frame board, in mm;

L is the length of the metal plate, in mm;

_L2 is the shortest distance between the edge of the mounting hole and the edge of the battery protection base plate, in mm.

Optionally, the battery protection base plate meets the following conditions:

0.45≤-D*lg(d ₀ *W/L)/L ₂ ≤1.7.

Optionally, the diameter D of the mounting hole is 4.5-10 mm.

Optionally, the total thickness _d0 of the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer is 1.6-4.0 mm.

Optionally, the width W of the frame plate is 30-200 mm.

Optionally, the length L of the metal plate is 1200-2200 mm.

Optionally, the shortest distance _L2 between the edge of the mounting hole and the edge of the battery protection bottom plate is 4 to 15 mm.

Optionally, the distance between two adjacent mounting holes is 60 to 140 mm.

Optionally, the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer are each independently selected from a glass fiber reinforced polyamide resin part, a glass fiber reinforced polypropylene resin part, a glass fiber reinforced polyethylene resin part, a glass fiber reinforced polycarbonate resin part or a glass fiber reinforced polystyrene resin part.

Optionally, the upper fiber-reinforced resin layer, the fiber-reinforced resin frame and the lower fiber-reinforced resin layer are all glass fiber-reinforced resin parts, the glass fiber-reinforced resin parts contain 50% to 70% of glass fibers, and the alkali content of the glass fibers is less than 0.8%.

Optionally, the upper fiber-reinforced resin layer comprises a plurality of first fiber-reinforced prepregs laminated on each other;

The fiber-reinforced resin frame includes multiple layers of second fiber-reinforced prepreg laminated on each other;

The lower fiber-reinforced resin layer includes a plurality of third fiber-reinforced prepregs stacked one on the other.

Optionally, the metal plate is a steel plate, and a galvanized layer, a galvanized iron alloy layer or an electrophoretic paint protective layer is provided on the outer surface of the steel plate.

On the other hand, the present invention provides a battery pack composite protection structure, including a battery pack and the battery protection bottom plate as described above, wherein the battery protection bottom plate is arranged below the battery pack, and a buffer zone is formed between the battery pack and the battery protection bottom plate.

Optionally, the buffer zone is filled with a buffer layer, and the buffer layer is selected from a honeycomb material or a hard foam material.

On the other hand, the present invention provides a vehicle comprising the battery protection floor or the battery pack composite protection structure as described above.

According to the battery protection base plate provided by the present invention, the upper fiber reinforced resin layer and the lower fiber reinforced resin layer are compounded on the front and back surfaces of the metal plate. On the one hand, the upper fiber reinforced resin layer and the lower fiber reinforced resin layer can improve the corrosion resistance of the metal plate. At the same time, the lower fiber reinforced resin layer can resist the impact of stones and the like on the bottom of the battery protection base plate, avoiding corrosion problems at the impact site. On the other hand, after the upper fiber reinforced resin layer and the lower fiber reinforced resin layer are compounded with the metal plate, the stiffness and strength of the metal plate are effectively improved, and the metal plate has higher impact resistance.

Furthermore, the frame position of the battery protection bottom plate is used for the installation of the battery protection bottom plate at the bottom of the battery pack, which affects the installation stability of the battery protection bottom plate and the amplitude strength of the battery protection bottom plate when it is impacted. The inventors have found through a large number of experiments that when the diameter D of the mounting hole, the total thickness d ₀ of the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer, the width W of the frame plate, the length L of the metal plate and the shortest distance L ₂ between the edge of the mounting hole and the edge of the battery protection bottom plate meet the condition: 0.4≤-D*lg(d ₀ *W/L)/L ₂ ≤2, it is beneficial to reduce the amplitude strength of the battery protection bottom plate when it is impacted, avoid the problem of its connecting parts loosening under long-term vibration conditions, and reduce the delamination phenomenon between the upper fiber reinforced resin layer, the metal plate and the lower fiber reinforced resin layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of a battery protection base plate provided by the present invention;

FIG2 is a schematic diagram of the matching of the metal plate and the fiber reinforced resin frame provided by the present invention;

3 is a schematic diagram of the structure of different first fiber-reinforced prepreg unidirectional tapes in the upper fiber-reinforced resin layer provided by the present invention;

FIG4 is a schematic diagram of the structure of different first fiber woven cloth reinforced prepregs in the upper fiber reinforced resin layer provided by the present invention;

FIG5 is a schematic structural diagram of a composite protection structure for a battery pack provided by the present invention;

FIG6 is an enlarged schematic diagram of point A in FIG5 ;

FIG7 is a schematic diagram of a bottom cross-section of a battery pack composite protection structure provided by an embodiment of the present invention;

FIG8 is a schematic bottom cross-sectional view of a battery pack composite protection structure provided by another embodiment of the present invention;

FIG9 is a schematic bottom cross-sectional view of a battery pack composite protection structure provided in another embodiment of the present invention.

The reference numerals in the drawings of the specification are as follows:

1. Battery protection bottom plate; 11. Upper fiber reinforced resin layer; 111. First fiber reinforced prepreg unidirectional tape; 112. First fiber woven cloth reinforced prepreg; 12. Metal plate; 13. Fiber reinforced resin frame; 131. Frame plate; 14. Lower fiber reinforced resin layer; 15. Mounting hole; 2. Buffer layer; 3. Battery pack; 31. Tray; 4. Buffer zone.

DETAILED DESCRIPTION

In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

Referring to FIGS. 1 , 2 and 6 , an embodiment of the present invention provides a battery protection base plate 1, comprising an upper fiber reinforced resin layer 11, a metal plate 12, a fiber reinforced resin frame 13 and a lower fiber reinforced resin layer 14, wherein the metal plate 12 and the fiber reinforced resin frame 13 are located between the upper fiber reinforced resin layer 11 and the lower fiber reinforced resin layer 14, wherein the fiber reinforced resin frame 13 is a frame structure formed by connecting a plurality of frame plates 131 end to end, wherein the metal plate 12 is located inside the fiber reinforced resin frame 13, wherein the top surface of the fiber reinforced resin frame 13 is integrally connected to the upper fiber reinforced resin layer 11, and the bottom surface of the fiber reinforced resin frame 13 is integrally connected to the lower fiber reinforced resin layer 14; a plurality of mounting holes 15 are spaced apart on the inner side of the edge of the battery protection base plate 1, wherein the mounting holes 15 sequentially pass through the upper fiber reinforced resin layer 11, the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14, and wherein the battery protection base plate 1 meets the following conditions:

0.4≤-D*lg(d ₀ *W/L)/L ₂ ≤2

Wherein, D is the diameter of the mounting hole 15, in mm;

_d0 is the total thickness of the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer, in mm;

W is the width of the frame board, in mm;

L is the length of the metal plate 12, in mm;

_L2 is the shortest distance between the edge of the mounting hole 15 and the edge of the battery protection base plate 1, in mm.

As shown in FIG6 , the shortest distance L ₂ between the edge of the mounting hole and the edge of the battery protection bottom plate specifically refers to: selecting two points on the edge of the mounting hole 15 and the edge of the battery protection bottom plate 1 respectively, the shortest connection length between the two points is the shortest distance L ₂ between the edge of the mounting hole and the edge of the battery protection bottom plate.

It should be noted that, in the above relationship, the length L of the metal plate 12 is the length of the longer side of the metal plate 12 .

A fiber reinforced resin frame 13 is arranged on the periphery of the metal plate 12 as a transition piece for connecting the frame position of the upper fiber reinforced resin layer 11 and the lower fiber reinforced resin layer 14, which can effectively offset the influence of the thickness of the metal plate 12 on the frame connection of the upper fiber reinforced resin layer 11 and the lower fiber reinforced resin layer 14, which is beneficial to improve the overall thickness and tensile shear strength of the installation position, ensure the frame position strength of the battery protection base plate 1, and further facilitate to use the frame position of the battery protection base plate 1 as its installation structure on the battery, thereby improving its impact resistance.

The mounting hole 15 is used for mounting and fastening the battery protection bottom plate 1 at the bottom of the battery pack 3. By setting the mounting hole 15 on the inner side of the edge of the battery protection bottom plate 1 and sequentially passing through the upper fiber reinforced resin layer 11, the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14, it is possible to avoid the mounting hole 15 passing through the metal plate 12, thereby avoiding corrosion problems caused by the metal plate 12 being exposed at the mounting hole 15.

The frame position of the battery protection bottom plate 1 is used for the installation of the battery protection bottom plate 1 at the bottom of the battery pack 3, which affects the installation stability of the battery protection bottom plate 1 and the amplitude strength generated when the battery protection bottom plate 1 is impacted.

The inventors have found through a large number of experiments that when the diameter D of the mounting hole 15, the total thickness d ₀ of the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer, the width W of the frame plate, the length L of the metal plate 12 and the shortest distance L ₂ between the edge of the mounting hole 15 and the edge of the battery protection bottom plate 1 meet the condition: 0.4≤-D*lg(d ₀ *W/L)/L ₂ ≤2, it is beneficial to reduce the amplitude strength of the battery protection bottom plate 1 when it is impacted, avoid the problem of its connecting parts loosening under long-term vibration conditions, and reduce the delamination phenomenon between the upper fiber reinforced resin layer 11, the metal plate 12 and the lower fiber reinforced resin layer 14.

In some embodiments, the battery protection base plate 1 meets the following conditions:

0.45≤-D*lg(d ₀ *W/L)/L ₂ ≤1.7.

The above relationship is defined to help comprehensively consider the influence of factors such as the diameter D of the mounting hole 15, the total thickness _d0 of the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer, the width W of the frame plate, the length L of the metal plate 12 and the shortest distance _L2 between the edge of the mounting hole 15 and the edge of the battery protection bottom plate 1 on the vibration resistance and impact resistance of the battery protection bottom plate 1, thereby obtaining a battery protection bottom plate 1 with higher stability.

In some embodiments, a plurality of the mounting holes 15 are disposed around the outer circumference of the metal plate 12 to evenly disperse the top gravity and the bottom impact force on the metal plate 12 .

Specifically, during installation, a connecting piece is arranged to pass through the installation hole 15 to fix the battery protection base plate 1 to the bottom of the battery pack 3, and the connecting piece is a rivet, a screw or a bolt.

In some embodiments, the diameter D of the mounting hole 15 is 4.5-10 mm.

Specifically, the diameter D of the mounting hole 15 may be 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm or 10 mm.

The diameter D of the mounting hole 15 is related to the force on the battery protection base plate 1 at the mounting position. As the diameter D of the mounting hole 15 increases, the force area of the mounting position of the battery protection base plate 1 increases under vibration and impact conditions. At the same time, since the area of the mounting hole 15 in the battery protection base plate 1 increases, the overall strength of the frame position of the battery protection base plate 1 decreases. When the diameter D of the mounting hole 15 is within the above range, the problem of stress concentration can be avoided, while reducing the impact on the strength of the frame position of the battery protection base plate 1 and improving the impact resistance.

In some embodiments, the total thickness _d0 of the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer is 1.6-4.0 mm.

Specifically, the total thickness _d0 of the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer can be 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.3mm, 2.5mm, 2.6mm, 2.8mm, 2.9mm, 3.0mm, 3.1mm, 3.3mm, 3.5mm, 3.6mm, 3.8mm, 3.9mm or 4.0mm.

The total thickness _d0 of the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer affects the mechanical strength of the battery protection base plate 1 at the frame position. When the total thickness _d0 of the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer increases, the mechanical strength of the battery protection base plate 1 at the frame position also gradually increases, but its material cost increases accordingly, and at the same time leads to an increase in the distance from the ground; when the total thickness _d0 of the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer is within the above range, it can have a better supporting and stabilizing effect while ensuring that it is as light as possible.

In some embodiments, the width W of the frame plate is 30-200 mm.

Specifically, the width W of the frame plate may be 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, 130 mm, 140 mm, 150 mm, 160 mm, 170 mm, 180 mm, 190 mm or 200 mm.

When the width W of the frame plate is within the above range, the battery protection base plate 1 has a suitable installation area, which effectively supports and positions the metal plate 12 in the middle thereof.

In some embodiments, the length L of the metal plate 12 is 1200-2200 mm.

Specifically, the length L of the metal plate 12 may be 1200 mm, 1400 mm, 1500 mm, 1600 mm, 1700 mm, 1800 mm, 1900 mm, 2000 mm, 2100 mm or 2200 mm.

The length L of the metal plate 12 is determined according to the length of the battery pack 3 to be protected, so that the metal plate 12 can cover the bottom position of the battery pack 3 as much as possible to achieve a better protection effect.

In some embodiments, the shortest distance _L2 between the edge of the mounting hole 15 and the edge of the battery protection bottom plate 1 is 4 to 15 mm.

Specifically, the shortest distance _L2 between the edge of the mounting hole 15 and the edge of the battery protection base plate 1 can be 4 mm, 5 mm, 7 mm, 8 mm, 9 mm, 10 mm, 12 mm, 14 mm or 15 mm.

The portion between the mounting hole 15 and the edge of the battery protection base plate 1 is used to bear the tensile force of the battery protection base plate 1 when it is impacted. When the shortest distance _L2 between the edge of the mounting hole 15 and the edge of the battery protection base plate 1 is within the above range, it is beneficial to maintain the morphological stability of the edge position of the battery protection base plate 1 when it is impacted, and avoid deformation of the mounting hole 15.

In some embodiments, the distance between two adjacent mounting holes 15 is 60-140 mm.

When the distance between two adjacent mounting holes 15 is within the above range, the frame position of the battery protection base plate 1 can be fixed, avoiding the problem of gaps between the mounting holes 15 caused by excessive spacing between the mounting holes 15, and having a better dispersion effect on impact force.

In different embodiments, the resins of the upper fiber reinforced resin layer 11, the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14 are independently selected from thermosetting and/or thermoplastic materials. Examples may include, but are not limited to, epoxy resins, phenolic plastics, phenols, cyanates, imides (e.g., polyimide, bismaleimide (BMI), polyetherimide), polypropylenes, polyesters, benzoxazines, polybenzimidazoles, polybenzothiazoles, polyamides, polyamide-imides, polysulfones, polyethersulfones, polycarbonates, polyethylene terephthalate and polyetherketones (e.g., polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), etc.) and combinations thereof.

In different embodiments, the fibers of the upper fiber reinforced resin layer 11 , the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14 are independently selected from glass fibers, aramid fibers, carbon fibers, graphite fibers, boron fibers, aromatic polyamide fibers and mixtures thereof.

The fibers of the upper fiber reinforced resin layer 11 , the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14 may be embedded in the resin in the form of chopped fibers, chopped fibers, non-woven fabrics, unidirectional reinforced fiber substrates, woven fabrics, and the like.

In some embodiments, the upper fiber reinforced resin layer 11, the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14 are each independently selected from glass fiber reinforced polyamide resin parts or glass fiber reinforced polypropylene resin parts, glass fiber reinforced polyethylene resin parts, glass fiber reinforced polycarbonate resin parts or glass fiber reinforced polystyrene resin parts.

In some embodiments, the upper fiber reinforced resin layer 11, the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14 are made of the same resin material. The same resin material can ensure the affinity of the materials between different layers, thereby ensuring the degree of integration between different layers and improving the overall strength.

In some embodiments, the upper fiber reinforced resin layer 11, the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14 are all glass fiber reinforced resin parts, and the glass fiber reinforced resin parts contain 50% to 70% glass fiber, which is beneficial to improving the material strength of the upper fiber reinforced resin layer 11, the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14.

In some embodiments, the glass fibers have an alkali content of <0.8%.

When the alkali content of the glass fiber is lower than 0.8%, it is beneficial to improve the anti-aging performance of the upper fiber reinforced resin layer 11, the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14, and slow down the performance degradation of the materials after long-term use.

In some embodiments, the glass fiber is selected from E glass fiber or S glass fiber.

In some embodiments, the upper fiber-reinforced resin layer 11 includes a plurality of first fiber-reinforced prepregs stacked on top of each other;

The fiber-reinforced resin frame 13 includes multiple layers of second fiber-reinforced prepreg laminated on each other;

The lower fiber-reinforced resin layer 14 includes a plurality of third fiber-reinforced prepregs stacked one on another.

As shown in Figure 3, in one embodiment, the upper fiber reinforced resin layer 11 includes multiple layers of first fiber reinforced prepreg unidirectional tapes 111 stacked on each other, the fiber arrangement direction of two adjacent layers of the first fiber reinforced prepreg unidirectional tapes 111 is approximately 90° staggered, and the allowable deviation range of the ply angle of two adjacent layers of the first fiber reinforced prepreg unidirectional tapes 111 is ±20°.

The fibers in the first fiber reinforced prepreg unidirectional tape 111 are arranged unidirectionally. When subjected to a tensile force along the fiber extension direction, the fibers in the first fiber reinforced prepreg unidirectional tape 111 can effectively bear the tensile force. By arranging the fibers of adjacent first fiber reinforced prepreg unidirectional tapes in an approximately 90° staggered manner, it is beneficial to improve the uniformity of force on the upper fiber reinforced resin layer 11 in all directions.

The fiber reinforced resin frame 13 includes multiple layers of second fiber reinforced prepreg unidirectional tapes stacked on each other, the fibers in the second fiber reinforced prepreg unidirectional tapes are arranged unidirectionally, the fiber arrangement directions of two adjacent layers of the second fiber reinforced prepreg unidirectional tapes are staggered at approximately 90°, and the allowable deviation range of the ply angle of two adjacent layers of the second fiber reinforced prepreg unidirectional tapes is ±20°.

The lower fiber reinforced resin layer 14 includes multiple layers of third fiber reinforced prepreg unidirectional tapes stacked on each other, the fibers in the third fiber reinforced prepreg unidirectional tapes are arranged unidirectionally, the fiber arrangement directions of two adjacent layers of the third fiber reinforced prepreg unidirectional tapes are staggered at approximately 90°, and the allowable deviation range of the ply angle of two adjacent layers of the third fiber reinforced prepreg unidirectional tapes is ±20°.

The fiber arrangement of the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14 is similar to that of the upper fiber reinforced resin layer 11 , and will not be described in detail.

As shown in FIG. 4 , in another embodiment, the upper fiber reinforced resin layer 11 includes a plurality of first fiber woven cloth reinforced prepregs 112 stacked on top of each other, wherein the fibers in the first fiber woven cloth reinforced prepregs 112 form a woven cloth in an interlaced manner.

The fiber reinforced resin frame 13 includes a plurality of second fiber woven cloth reinforced prepregs stacked on each other, wherein the fibers in the second fiber woven cloth reinforced prepregs are woven in an interlaced manner.

The lower fiber-reinforced resin layer 14 includes a plurality of mutually stacked third fiber woven cloth reinforced prepregs, wherein the fibers in the third fiber woven cloth reinforced prepregs are woven in an interlaced manner.

In some embodiments, the metal plate 12 is selected from iron and its alloys, aluminum and its alloys, magnesium and its alloys, copper and its alloys, titanium and its alloys, or nickel and its alloys.

In some embodiments, the metal plate 12 is a steel plate, and the outer surface of the steel plate is provided with a galvanized layer, a galvanized iron alloy layer or an electrophoretic paint protective layer.

Compared with other metal materials, the steel plate used as the metal plate 12 has better tensile strength and elongation, can meet the impact resistance requirements, and is beneficial to improving the protection of the battery pack 3.

A galvanized layer, a galvanized iron alloy layer or an electrophoretic paint protective layer is arranged on the outer surface of the steel plate to improve the anti-corrosion performance of the steel plate. When the upper fiber reinforced resin layer 11 or the fiber reinforced resin layer 14 is damaged, the galvanic cell effect formed by the galvanized layer or the galvanized iron alloy layer and the steel plate causes the galvanized layer or the galvanized iron alloy layer to corrode before the steel plate, thereby protecting the steel plate. The electrophoretic paint protective layer has good adhesion and can effectively isolate the steel plate from the external environment.

As shown in Figure 5, another embodiment of the present invention provides a battery pack composite protection structure, including a battery pack 3 and the battery protection bottom plate 1 as described above, wherein the battery protection bottom plate 1 is arranged below the battery pack 3, and a buffer zone 4 is formed between the battery pack 3 and the battery protection bottom plate 1.

Since the battery pack composite protection structure adopts the above-mentioned battery protection bottom plate 1, the protection strength of the battery protection bottom plate 1 and the stable connection of the battery protection bottom plate 1 on the battery pack 3 are effectively guaranteed while ensuring a relatively low overall thickness.

In some embodiments, the battery pack 3 includes a tray 31 and batteries disposed on the tray 31 .

In different embodiments, the buffer zone 4 may be disposed between the battery pack 3 and the battery protection base plate 1 in different ways.

As shown in FIG. 7 , in one embodiment, a groove is provided inwardly on the bottom surface of the tray 31 to form the buffer zone 4 , and the battery protection bottom plate 1 is in the shape of a flat plate, and the battery protection bottom plate 1 covers the buffer zone 4 .

As shown in Figure 8, in one embodiment, the frame of the battery protection base plate 1 is connected to the bottom surface of the tray 31, and a groove is provided inwardly on the bottom surface of the tray 31. The battery protection base plate 1 protrudes away from the tray 31 to form the buffer zone 4 between the tray 31 and the battery protection base plate 1.

As shown in Figure 9, in one embodiment, the frame of the battery protection base plate 1 is connected to the bottom surface of the tray 31, the bottom surface of the tray 31 is a plane, and the battery protection base plate 1 protrudes away from the tray 31 to form the buffer zone 4 between the tray 31 and the battery protection base plate 1.

In some embodiments, the buffer zone 4 is filled with a buffer layer 2 , and the buffer layer 2 is selected from a honeycomb material or a hard foam material.

Honeycomb material or hard foam material can absorb the collapse deformation space of the battery protection plate under the action of strong external impact, buffer and absorb part of the energy of the strong external impact, prevent the compression deformation of the battery protection bottom plate 1 from impacting the internal battery cells of the battery pack 3, and further protect the battery pack 3.

In some embodiments, the honeycomb material is selected from PP honeycomb material or aluminum honeycomb material; the rigid foam material is selected from PU rigid foam material, PET rigid foam material, PMI rigid foam material, PVC rigid foam material, PET rigid foam material, MPP rigid foam material, PLA rigid foam material, PI rigid foam material or EPTU foam material.

Another embodiment of the present invention provides a vehicle, comprising the battery protection floor or the battery pack composite protection structure as described above.

The present invention is further described below by way of examples.

Table 1

Example 1

This embodiment is used to illustrate the battery pack composite protection structure disclosed in the present invention, including a battery pack, a buffer layer and a battery protection bottom plate, the battery protection bottom plate includes a metal plate, an upper fiber reinforced resin layer, a fiber reinforced resin frame and a lower fiber reinforced resin layer, the metal plate is located between the upper fiber reinforced resin layer and the lower fiber reinforced resin layer, the fiber reinforced resin frame is a frame structure formed by connecting a plurality of frame plates end to end, the metal plate is located inside the fiber reinforced resin frame, the top surface of the fiber reinforced resin frame is integrally connected to the upper fiber reinforced resin layer, and the bottom surface of the fiber reinforced resin frame is integrally connected to the lower fiber reinforced resin layer; the battery protection bottom plate is arranged below the battery pack, a buffer zone is formed between the battery pack and the battery protection bottom plate, the buffer zone is filled with the buffer layer, a plurality of mounting holes are opened at the frame position of the battery protection bottom plate, a tray is arranged at the bottom of the battery pack, and the battery protection bottom plate is mounted at the bottom frame position of the tray by rivets passing through the mounting holes.

Among them, the diameter D of the mounting hole is 10mm, the total thickness _d0 of the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer is 2.6mm, the width W of the frame plate is 100mm, the length L of the metal plate is 1600mm and the shortest distance _L2 between the edge of the mounting hole and the edge of the battery protection bottom plate is 5mm.

Embodiments 2 to 19

Examples 2 to 19 are used to illustrate the composite protection structure of the battery pack disclosed in the present invention, including most of the structures in Example 1, and the differences are as follows:

The battery protection base plate design parameters provided in Examples 2 to 19 in Table 1 are used.

Comparative Examples 1 to 3

Comparative Examples 1 to 3 are used to compare and illustrate the composite protection structure of the battery pack disclosed in the present invention, including most of the structures in Example 1, and the differences are:

The battery protection base plate design parameters provided in Comparative Examples 1 to 3 in Table 1 are used.

Performance Testing

The following performance tests were performed on the composite protection structures of the battery packs provided in the above embodiments and comparative examples:

The battery pack composite protection structure is installed on a vibration table and subjected to 30w mileage simulated vibration.

30w mileage simulated vibration test: According to the requirements of GB/T 2423.43, the test object is installed on the vibration table, and the torque of each installation point is tested and recorded. The vibration test is carried out in three directions. The test process refers to GB/T 2423.56. The specific test conditions are as follows:

First, random vibration was applied in the Z direction for 21 h (random vibration conditions are shown in Table 2), and then fixed frequency vibration was applied in the Z direction for 1 h (fixed frequency vibration conditions: 24 Hz fixed frequency, 1 g fixed frequency amplitude);

Secondly, random vibration was applied in the Y direction for 21 h (the random vibration conditions are shown in Table 2), and then fixed frequency vibration was applied in the Y direction for 1 h (fixed frequency vibration conditions: 24 Hz fixed frequency, 1 g fixed frequency amplitude);

Furthermore, random vibration was applied in the X direction for 21 h (the random vibration conditions are shown in Table 2), and then fixed-frequency vibration was applied in the X direction for 1 h (the fixed-frequency vibration conditions were: 24 Hz fixed-frequency frequency, 1 g fixed-frequency amplitude).

Among them, PSD stands for power spectral density, which represents the power spectral density of vibration at a certain frequency; the r.m.s. value represents the comprehensive acceleration of vibration and feedbacks the vibration intensity.

Table 2 Random vibration test

Use a vernier caliper to detect the diameters of multiple mounting holes after vibration, take the average value, and obtain the average diameter of the mounting holes after vibration. Take the diameter D of the mounting holes as the average diameter of the mounting holes before vibration, and calculate the percentage of the size increment of the mounting holes after vibration by the following formula:

The percentage of the mounting hole size increase after vibration = (the average diameter of the mounting hole after vibration - the average diameter of the mounting hole before vibration) / the diameter of the mounting hole before vibration * 100%

Record the installation of rivets after vibration and the tearing of the battery protection base plate around the rivets.

The test results obtained are entered in Table 3.

Table 3

It can be seen from the test results in Table 3 that by limiting the diameter D of the mounting hole, the total thickness d ₀ of the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer, the width W of the frame plate, the length L of the metal plate and the shortest distance L ₂ between the edge of the mounting hole and the edge of the battery protection bottom plate within the relationship 0.4≤-D*lg(d ₀ *W/L)/L ₂ ≤2, the installation stability of the battery protection bottom plate can be effectively guaranteed, and the problems of size enlargement, composite structure delamination and rivet loosening caused by poor hole durability can be avoided.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims (15)

1. A battery protective bottom plate, characterized in that it includes an upper fiber-reinforced resin layer, a metal plate, a fiber-reinforced resin frame and a lower fiber-reinforced resin layer, and the metal plate and the fiber-reinforced resin frame are located on the upper fiber-reinforced resin layer. Between the resin layer and the lower fiber-reinforced resin layer, the fiber-reinforced resin frame is a frame structure formed by connecting multiple frame plates end-to-end. The metal plate is located inside the fiber-reinforced resin frame. The fiber-reinforced resin frame is The top surface of the resin frame is integrally connected to the upper fiber-reinforced resin layer, and the bottom surface of the fiber-reinforced resin frame is integrally connected to the lower fiber-reinforced resin layer; a plurality of mounting holes are spaced inside the edge of the battery protection bottom plate. , the mounting holes pass through the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer in sequence, and the battery protection bottom plate meets the following conditions: 0.4≤-D*lg(d ₀ *W/L)/L ₂ ≤2 Among them, D is the diameter of the mounting hole, in mm; d ₀ is the total thickness of the upper fiber-reinforced resin layer, fiber-reinforced resin frame and lower fiber-reinforced resin layer, in mm; W is the width of the frame board, in mm; L is the length of the metal plate, in mm; L ₂ is the shortest distance between the edge of the mounting hole and the edge of the battery protection bottom plate, in mm. 2. The battery protective bottom plate according to claim 1, characterized in that the battery protective bottom plate meets the following conditions: 0.45≤-D*lg(d ₀ *W/L)/L ₂ ≤1.7. 3. The battery protective bottom plate according to claim 1, wherein the diameter D of the mounting hole is 4.5-10 mm. 4. The battery protective bottom plate according to claim 1, wherein the total thickness _d0 of the upper fiber-reinforced resin layer, fiber-reinforced resin frame and lower fiber-reinforced resin layer is 1.6 to 4.0 mm. 5. The battery protective bottom plate according to claim 1, wherein the width W of the frame plate is 30 to 200 mm. 6. The battery protective bottom plate according to claim 1, wherein the length L of the metal plate is 1200-2200 mm. 7. The battery protective bottom plate according to claim 1, wherein the shortest distance _L2 between the edge of the mounting hole and the edge of the battery protective bottom plate is 4 to 15 mm. 8. The battery protective bottom plate according to claim 1, wherein the distance between two adjacent mounting holes is 60 to 140 mm. 9. The battery protective bottom plate according to claim 1, wherein the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer are each independently selected from glass fiber reinforced polyamide resin. parts, glass fiber reinforced polypropylene resin parts, glass fiber reinforced polyethylene resin parts, glass fiber reinforced polycarbonate resin parts or glass fiber reinforced polystyrene resin parts. 10. The battery protective bottom plate according to claim 1, wherein the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer are all glass fiber reinforced resin parts, and the glass fiber reinforced resin The fiber-reinforced resin parts contain 50% to 70% glass fibers, and the alkali content of the glass fibers is <0.8%. 11. The battery protective bottom plate according to claim 1, wherein the upper fiber-reinforced resin layer includes multiple layers of mutually laminated first fiber-reinforced prepregs; The fiber-reinforced resin frame includes multiple layers of second fiber-reinforced prepreg laminated on each other; The lower fiber-reinforced resin layer includes multiple layers of third fiber-reinforced prepreg laminated on each other. 12. The battery protective bottom plate according to claim 1, wherein the metal plate is a steel plate, and the outer surface of the steel plate is provided with a galvanized layer, a galvanized iron alloy layer or an electrophoretic paint protective layer. 13. A battery pack composite protection structure, characterized by comprising a battery pack and a battery protection bottom plate as claimed in any one of claims 1 to 12, the battery protection bottom plate being disposed below the battery pack, A buffer zone is formed between the battery pack and the battery protective bottom plate. 14. The battery pack composite protective structure according to claim 13, wherein the buffer area is filled with a buffer layer, and the buffer layer is selected from honeycomb materials or hard foam materials. 15. A vehicle, characterized by comprising the battery protection bottom plate according to any one of claims 1 to 12, or the battery pack composite protection structure according to claims 13 or 14.