Lower box body and battery pack

Abstract

The utility model provides a lower box body and a battery pack, and relates to the technical field of batteries. The lower box body comprises a frame and a bottom plate; the frame comprises a front end plate and a plurality of side plates, and the front end plate and the side plates are sequentially connected end to end to form an enclosure frame structure; the bottom plate covers one end of the frame so as to seal one end of the inner cavity of the frame; and a chamfer structure is arranged at the joint between the bottom plate and the front end plate. In the application, the chamfering structure is arranged at the joint between the front end plate and the bottom plate, so that the ground clearance of one end, close to the forward direction of the automobile, of the lower box body is increased, and therefore, an obstacle can move to the lower part of the chamfering structure relative to the automobile based on the ground clearance, and further, the obstacle can upwards push the chamfering structure; and finally, the lower box body is lifted upwards under the action of an automobile chassis suspension, so that the battery pack crosses an obstacle. Therefore, the impact force of an obstacle on the battery pack can be relieved, and the impact protection performance of the battery pack can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a lower box and a battery pack. Background Art

[0002] In the related art, in order to facilitate the assembly and maintenance of new energy vehicles, the battery pack of new energy vehicles is usually installed on the chassis of the entire vehicle and is located below the chassis. Among them, the battery pack includes an upper box body and a lower box body that cover each other to form a storage cavity, a liquid cooling plate and a battery module arranged in the storage cavity. The lower box body is arranged close to the road surface where the new energy vehicle is traveling. Because there are obstacles on some roads used for new energy vehicles, the obstacles will collide with the front end plate of the battery pack facing the direction of travel of the vehicle and the end close to the road surface. The impact of the obstacle on the battery pack will cause damage to the lower box body at the least, and damage to the liquid cooling plate and battery module at the worst.

[0003] Currently, there are two main ways in the industry to protect battery packs from impact during vehicle driving. One is to increase the strength of the battery box through thickness and material, thereby improving the impact resistance of the battery box. In this way, the increased strength of the battery box means that the battery has a greater weight and higher material cost. The other is to use buffer structures such as interlayers to improve the impact resistance of the battery bottom guard plate. However, in this method, due to the limitations of the chassis height of new energy vehicles and the height of the battery pack, the addition of the buffer structure reduces the ground clearance of the battery pack, resulting in more contact between the battery pack with the buffer structure and obstacles, which in turn increases the frequency of the battery pack being impacted by obstacles. Utility Model Content

[0004] The embodiments of the present application provide a lower box and a battery pack, which can improve the impact protection of the battery pack.

[0005] In the first aspect, an embodiment of the present application provides a lower box body, which is applied to a battery pack, and the lower box body includes a frame and a bottom plate; the frame includes a front end plate and multiple side plates, and the front end plate and the multiple side plates are connected end to end in sequence to form a frame structure; the bottom plate covers one end of the frame to close one end of the inner cavity of the frame; wherein, a chamfer structure is provided at the connection between the bottom plate and the front end plate.

[0006] In one embodiment, the chamfered structure is a rounded chamfer with a radius of R satisfying: 20 mm ≤ R ≤ 50 mm.

[0007] In one embodiment, the thickness of the middle portion of the chamfered structure is d, the thickness of the bottom plate is d1, and the thickness of the front plate is d2, satisfying: d>d1, and d>d2.

[0008] In one embodiment, the thickness of the chamfered structure gradually decreases from the middle of the chamfered structure to both sides of the chamfered structure.

[0009] In one embodiment, the lower box further includes a reinforcement structure, which is disposed in the inner cavity of the frame and is configured to increase the strength of the chamfered structure.

[0010] In one embodiment, the reinforcement structure includes a first reinforcement plate, which is arranged in the inner cavity of the frame. The first reinforcement plate is arranged opposite to the chamfered structure, one side of the first reinforcement plate is connected to the front end plate, and the other side is connected to the bottom plate.

[0011] In one embodiment, along the extension direction of the chamfered structure, two ends of the first reinforcing plate are respectively connected to two oppositely disposed side plates.

[0012] In one embodiment, the reinforcement structure further includes a support member, which is located between the chamfered structure and the first reinforcement plate, with one end of the support member connected to the chamfered structure and the other end connected to the first reinforcement plate.

[0013] In one embodiment, the supporting member is a reinforcing plate or an elastic member.

[0014] In a second aspect, an embodiment of the present application provides a battery pack, comprising a battery module, an upper box and the aforementioned lower box; the upper box and the frame cover each other at one end facing away from the bottom plate to define an installation cavity; the battery module is disposed in the installation cavity.

[0015] In a third aspect, an embodiment of the present application further provides a battery pack comprising the aforementioned battery box.

[0016] Beneficial effects of the embodiments of the present application:

[0017] In an embodiment of the present application, a chamfered structure is provided at the junction between the front end panel and the bottom panel, thereby increasing the ground clearance at the end of the lower housing closest to the vehicle's forward travel direction. This allows obstacles to move relative to the vehicle below the chamfered structure based on this ground clearance, which in turn pushes upward against the chamfered structure. Ultimately, the vehicle's chassis suspension works to lift the lower housing upward, allowing the battery pack to clear the obstacle. Consequently, when an obstacle within the ground clearance of the chamfered structure contacts the chamfered structure, it generates a thrust force against the battery pack, causing it to move upward, thereby reducing the impact force of the obstacle on the battery pack and improving the battery pack's impact resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 11 is a schematic structural diagram of the lower box provided in an embodiment of the present application;

[0020] Figure 2 This is a force analysis diagram of the chamfered structure provided in an embodiment of the present application;

[0021] Figure 3 is a schematic diagram of a chamfered structure provided by an embodiment of the present application being pushed by an obstacle;

[0022] Figure 4 This is a schematic diagram of the lower box passing over an obstacle provided by an embodiment of the present application;

[0023] Figure 5 This is a partial side view of the lower box provided in an embodiment of the present application;

[0024] Figure 6 is a top view of the lower box provided in an embodiment of the present application;

[0025] Figure 7 It is along Figure 6 Cross-sectional view of AA;

[0026] Figure 8 Schematic diagram of the cooperation between the support member and the chamfered structure provided in an embodiment of the present application;

[0027] Description of reference numerals:

[0028] 001-lower box;

[0029] 011-frame; 111-front panel; 112-side panel;

[0030] 012-bottom plate; 013-chamfered structure; 131-slide groove; 014-first reinforcement plate; 015-support member;

[0031] 002-Obstacle. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0033] Furthermore, it should be understood that the specific embodiments described herein are intended only to illustrate and explain the present application and are not intended to limit the present application. In this application, unless otherwise indicated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the directions of the drawings in the accompanying drawings; whereas "inner" and "outer" refer to the outline of the device.

[0034] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the specified features. In the description of this application, "plurality" means two or more, unless otherwise specifically specified.

[0035] In the description of this application, it should be noted that, unless otherwise specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0036] In the description of the embodiments of this application, words such as "example" or "for example" are used to indicate an example, illustration, or description. Any embodiment or design described as "for example" or "for example" in the embodiments of this application is not to be construed as being preferred or having more advantages than another embodiment or design. The use of words such as "example" or "for example" is intended to clearly present relative concepts.

[0037] See also Figure 1 , Figure 1 : It is a structural schematic diagram of the lower box body 001 provided in an embodiment of the present application. An embodiment of the present application provides a lower box body 001, which is applied to a battery pack. The lower box body 001 includes a frame 011 and a bottom plate 012. The frame 011 includes a front end plate 111 and a plurality of side plates 112. The front end plate 111 and the plurality of side plates 112 are connected end to end in sequence to form a frame structure. The bottom plate 012 covers one end of the frame to close one end of the inner cavity of the frame 011. Among them, a chamfer structure 013 is provided at the connection between the bottom plate 012 and the front end plate 111.

[0038] It is understood that the lower box 001 is generally a rectangular structure, and the frame 011 includes a front panel 111 and three side panels 112. The front panel 111 and the three side panels 112 are the four sides of the rectangle. The front panel 111 is the portion of the battery box facing the direction of the vehicle's travel.

[0039] In addition, the chamfered structure 013 between the bottom plate 012 and the front end plate 111 can be formed by bending the plate, or by integrally casting the bottom plate 012, the front end plate 111 and the chamfered structure 013, or by hot rolling, or by separately forming the bottom plate 012, the fillet and the front end plate 111 and then welding them together.

[0040] Exemplarily, the chamfer structure 013 is a rounded chamfer or a right-angle chamfer.

[0041] When the front end plate 111 faces an obstacle on the road, as the car moves, the chamfered structure 013 near the front end plate 111 contacts the obstacle. At this time, the forward momentum of the car generates a thrust on the obstacle. The obstacle generates a reaction force F based on this thrust. 反 Give the lower box 001. The reaction force F 反 Decomposed into two mutually perpendicular components, one of which is the reverse thrust F that hinders the car from moving forward 反推 , the other component is the vertical upward lifting force F v ,like Figure 2 As shown, Figure 2 This is a force analysis diagram of the chamfer structure 013 provided in the embodiment of the present application. v Under the action of the upward acceleration, the lower box 001 is lifted upward in coordination with the automobile chassis suspension. Figure 3 As shown, Figure 3 This is a schematic diagram of the chamfered structure 013 provided by the embodiment of the present application being pushed by an obstacle. As a result, the obstacle moves from the side of the chamfered structure 013 close to the front end plate 111 to the side of the chamfered structure 013 close to the bottom plate 012, and then moves from the side of the chamfered structure 013 close to the bottom plate 012 to the bottom of the bottom plate 012, until the lower box 001 crosses the obstacle. Figure 4 As shown, Figure 4 This is a schematic diagram of the lower box 001 provided in an embodiment of the present application crossing an obstacle.

[0042] In this embodiment, by providing a chamfered structure 013 at the junction between the front end panel 111 and the bottom panel 012, the ground clearance at the end of the lower housing 001 closest to the vehicle's forward direction is increased. This allows obstacles to move relative to the vehicle below the chamfered structure 013 based on this ground clearance. This allows the obstacle to push upward against the chamfered structure 013, ultimately lifting the lower housing 001 upward in coordination with the vehicle's chassis suspension, allowing the battery pack to clear the obstacle. Consequently, when an obstacle within the ground clearance of the chamfered structure 013 contacts the chamfered structure 013, it generates a thrust force against the battery pack, causing it to move upward, thereby reducing the impact force of the obstacle on the battery pack and improving the battery pack's impact resistance.

[0043] See also Figure 5 , Figure 5 001 is a partial side view of the lower box body 001 provided in an embodiment of the present application. In one embodiment, the chamfer structure 013 is a rounded chamfer structure.

[0044] It is understood that one side of the fillet is tangent to the outer wall of the front end plate 111, and the other side is tangent to the outer wall of the bottom plate 012. Thus, the outer wall of the bottom plate 012 smoothly transitions to the outer wall of the front end plate 111 through the fillet.

[0045] In this embodiment, by setting the chamfered structure 013 with rounded corners, on the one hand, the obstacle can be transitioned from the chamfered structure 013 to the bottom wall of the bottom plate 012 more smoothly, thereby reducing the vibration amplitude of the lower box 001; on the other hand, the stress state of the chamfered structure 013 can be improved, so that the chamfered structure 013 can disperse the remaining stress caused by the collision with the obstacle to a larger area, thereby reducing the stress in the contact area between the chamfered structure 013 and the obstacle, and then improving the impact resistance of the chamfered structure 013.

[0046] In addition, the rounded chamfered structure 013 has better bending bearing capacity and lower stress concentration. Therefore, compared with the right-angled chamfered structure, the rounded chamfered structure 013 is less likely to break when impacted.

[0047] In one embodiment, the radius of the rounded corner is R, which satisfies: 20 mm ≤ R ≤ 50 mm.

[0048] It will be understood that the radius R of the fillet includes but is not limited to 20mm, 25mm, 28mm, 30mm, 35mm, 39mm, 40mm, 45mm, 46mm, and 50mm.

[0049] Generally, the height of obstacles on the road that may impact the lower box 001 is mostly concentrated between 150mm and 200mm. The overlapping size of the obstacles in this interval with the lower box 001 in height is within 50mm. Although the larger the radius of the fillet, the higher the height of the obstacle that the lower box 001 can adapt to, the more conducive it is to lifting the lower box 001. However, if the fillet is too large, it will affect the arrangement of electrical components inside the lower box 001, and will also compress the space of the socket on the front end plate 111. Therefore, in this embodiment, the radius of the fillet is set between 20 and 50mm, so that the fillet can improve the impact protection of the battery pack while having little effect on the arrangement of electrical components inside the lower box 001.

[0050] See also Figure 6 and Figure 7 , Figure 6 This is a top view of the lower box 001 provided in an embodiment of the present application. Figure 7 It is along Figure 6 In one embodiment, the thickness of the middle portion of the chamfered structure 013 is d, the thickness of the bottom plate 012 is d1, and the thickness of the front plate 111 is d2, satisfying: d>d1, and d>d2.

[0051] For example, d1 = d2. It's understandable that the chamfered structure 013 requires a certain thickness to improve the battery pack's impact resistance, so a minimum thickness limit is set for the chamfered structure 013. To avoid affecting other structural arrangements, a maximum limit is set for the chamfered structure 013 between the front plate 111 and the bottom plate 012. When the maximum value of the chamfered structure 013 is constant, the greater its thickness, the greater the amplitude of change at the transition between the chamfered structure 013 and the front plate 111 and the bottom plate 012, the more likely it is to generate stress concentration, which in turn adversely affects the strength of the chamfered structure 013. Therefore, a maximum limit is set for the thickness of the chamfered structure 013 relative to the bottom plate 012 and the front plate 111. Therefore, 2d1 ≤ d ≤ 5d1. It's understandable that d includes, but is not limited to, 2d1, 2.5d1, 3d1, 4d1, and 5d1. For example, d1 = 3mm, and 6mm ≤ d ≤ 15mm.

[0052] In this embodiment, by thickening the chamfered structure 013, on the one hand, the strength of the chamfered structure 013 can be improved, thereby further improving the impact protection of the battery pack; on the other hand, only thickening the chamfered structure 013 can effectively control the overall thickness of the lower box body 001, thereby controlling the weight of the lower box body 001 and improving the material cost of the lower box body 001.

[0053] See also Figure 7 In one embodiment, the thickness of the chamfered structure 013 gradually decreases from the middle of the chamfered structure 013 to both sides of the chamfered structure 013 .

[0054] It can be understood that the middle portion of the chamfered structure 013 has the largest thickness, one side of the chamfered structure 013 is connected to the front end plate 111 , and the other side is connected to the bottom plate 012 .

[0055] In this embodiment, by gradually reducing the thickness of the chamfered structure 013, the thickness of the chamfered structure 013 changes linearly, thereby avoiding stress concentration areas in the chamfered structure 013 during impact, thereby improving the strength of the chamfered structure 013 and enhancing impact protection.

[0056] See also Figure 7 In one embodiment, the lower box body 001 further includes a reinforcement structure, which is disposed in the inner cavity of the frame 011 , and is configured to increase the strength of the chamfered structure 013 .

[0057] The reinforcement structure includes but is not limited to reinforcement plates, reinforcement ribs and other structures.

[0058] Specifically, the reinforcement structure may include reinforcing ribs provided on the chamfered structure 013. The provision of the reinforcing ribs can, on the one hand, increase the thickness of the chamfered structure 013, thereby increasing the strength of the chamfered structure 013; on the other hand, the reinforcing ribs can disperse the impact force borne by the chamfered structure 013, thereby improving the stress state of the chamfered structure 013 and further enhancing the collision resistance of the lower box 001.

[0059] In addition, the reinforcement structure may further include a first reinforcement plate 014. The first reinforcement plate 014 is disposed in the inner cavity of the frame 011. The first reinforcement plate 014 is disposed opposite to the chamfered structure 013. One side of the first reinforcement plate 014 is connected to the front end plate 111, and the other side is connected to the bottom plate 012.

[0060] Exemplarily, two ends of the first reinforcing plate 014 are welded to the front end plate 111 and the bottom plate 012 respectively.

[0061] In this embodiment, by providing a reinforcement structure, the strength of the chamfered structure 013 can be increased, thereby further improving the impact protection of the battery pack.

[0062] See also Figure 6 In one embodiment, along the extension direction of the chamfered structure 013 , both ends of the first reinforcing plate 014 are respectively connected to two oppositely disposed side plates 112 .

[0063] It can be understood that the extending direction of the chamfered structure 013 is parallel to the front end plate 111 and the bottom plate 012 .

[0064] In this embodiment, the above arrangement can improve the structural reliability of the first reinforcing plate 014 and the lower box 001, thereby improving the impact protection of the battery pack.

[0065] See also Figure 7 In one embodiment, the lower box 001 further includes a support member 015. The support member 015 is located between the chamfered structure 013 and the first reinforcing plate 014. One end of the support member 015 is connected to the chamfered structure 013, and the other end is connected to the first reinforcing plate 014.

[0066] Exemplarily, the support member 015 is vertically connected to the first reinforcing plate 014 .

[0067] In this embodiment, by providing the support member 015 , the strength of the chamfered structure 013 can be increased, thereby further improving the impact protection of the battery pack.

[0068] In one embodiment, the support member 015 includes but is not limited to a reinforcing plate or an elastic member.

[0069] It can be understood that when the support member 015 is a reinforcing plate, the chamfered structure 013 can be strengthened, thereby improving the strength of the lower box body 001 and further improving the anti-collision performance of the lower box body 001.

[0070] In addition, when the support member 015 is an elastic member, when the chamfered structure 013 is hit, it can absorb part of the impact force, thereby improving the stress state of the lower box body 001 and further enhancing the anti-collision performance of the lower box body 001.

[0071] See also Figure 8 , Figure 8 Schematic diagram of the support member 015 and the chamfered structure 013 provided in an embodiment of the present application. A slide groove 131 is provided on the side of the chamfered structure 013 facing the first reinforcing plate 014, and the side of the support member 015 facing away from the first reinforcing plate 014 is plugged into the slide groove 131.

[0072] As can be understood, support member 015 is welded to chamfered structure 013. During welding, support member 015 needs to be positioned to maintain a predetermined position. To facilitate welding, a slide groove 131 is provided on the side of chamfered structure 013 facing first reinforcing plate 014. This allows the side of support member 015 facing away from first reinforcing plate 014 to engage with slide groove 131. This allows support member 015 to be fixed in position via slide groove 131. Welding is then performed at the notch of slide groove 131 to weld support member 015 to chamfered structure 013. This improves the ease with which support member 015 can be connected to chamfered structure 013.

[0073] Accordingly, an embodiment of the present application provides a battery pack, including a battery module, an upper box and the aforementioned lower box 001; the upper box and the frame 011 cover each other at one end facing away from the bottom plate 012 to define an installation cavity; the battery module is arranged in the installation cavity.

[0074] It is understood that the upper box body is connected to the chassis of the automobile. The lower box body 001 is detachably connected to the upper box body through a locking member such as a screw.

[0075] In this embodiment, the use of the aforementioned lower case 001 increases the ground clearance at the end of the battery pack closest to the vehicle's forward direction. This allows obstacles to move relative to the vehicle below the chamfered structure 013 based on this ground clearance. This allows the obstacle to push upward against the chamfered structure 013, ultimately lifting the battery pack upward in coordination with the vehicle's chassis suspension, allowing the battery pack to cross the obstacle. Consequently, when an obstacle within the ground clearance of the chamfered structure 013 contacts the chamfered structure, it generates a thrust force against the battery pack, causing it to move upward, thereby reducing the impact force of the obstacle on the battery pack and improving the battery pack's impact resistance.

[0076] The above is a detailed introduction to the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, based on the ideas of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A lower box, applied to a battery pack, characterized in that: The lower box includes: The frame comprises a front end plate and a plurality of side plates, wherein the front end plate and the plurality of side plates are sequentially connected end to end to form a surrounding frame structure; a bottom plate, covering one end of the frame to close one end of the inner cavity of the frame; Wherein, a chamfer structure is provided at the connection between the bottom plate and the front end plate.

2. The lower box according to claim 1, characterized in that: The chamfered structure is a rounded chamfer, and the radius of the rounded corner is R, which satisfies: 20mm≤R≤50mm.

3. The lower box according to claim 1, characterized in that: The thickness of the middle portion of the chamfered structure is d, the thickness of the bottom plate is d1, and the thickness of the front end plate is d2, satisfying: d>d1, and d>d2.

4. The lower box according to claim 3, characterized in that: The thickness of the chamfered structure gradually decreases from the middle of the chamfered structure to both sides of the chamfered structure.

5. The lower box according to any one of claims 1 to 4, characterized in that: The lower box body further includes a reinforcement structure, which is disposed in the inner cavity of the frame and is configured to increase the strength of the chamfered structure.

6. The lower box according to claim 5, characterized in that: The reinforcement structure includes a first reinforcement plate, which is arranged in the inner cavity of the frame. The first reinforcement plate is arranged opposite to the chamfered structure. One side of the first reinforcement plate is connected to the front end plate, and the other side is connected to the bottom plate.

7. The lower box according to claim 6, characterized in that: Along the extending direction of the chamfered structure, two ends of the first reinforcing plate are respectively connected to the two oppositely arranged side plates.

8. The lower box according to claim 6, characterized in that: The reinforcement structure further includes a support member, which is located between the chamfered structure and the first reinforcement plate. One end of the support member is connected to the chamfered structure, and the other end is connected to the first reinforcement plate.

9. The lower box according to claim 8, characterized in that: The supporting member is a reinforcing plate or an elastic member.

10. A battery pack, characterized in that: include: The lower box according to any one of claims 1 to 9; An upper box body, covering an end of the frame away from the bottom plate to define a mounting cavity; The battery module is arranged in the installation cavity.

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