Fixing plate, battery pack and electric device
By designing a fixed plate with a specific groove and weak area size relationship, the problem of battery cell expansion causing the fixing plate to break, achieving effective restrictions on the expansion of the battery cell group and increasing the strength of the fixed plate.
Patent Information
- Application Number
- CN202421134160.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-20
- Publication Date
- 2025-04-01
- Estimated Expiration
- 2034-05-20
AI Technical Summary
The existing fixing plate cannot effectively limit the expansion of the battery cell, resulting in the easy breakage of the end of the fixing plate.
A fixing plate is designed, including a first section fixing plate and a second section fixing plate. A first groove is provided on the first section fixing plate and a second groove is provided on the second section fixing plate. By adjusting the size of the weak area of the second section fixing plate and the positional relationship of the first groove, a specific numerical range is satisfied to improve overall stress concentration.
Through this design, the breakage of the second section of the fixing plate is avoided, the expansion of the battery cell group is effectively limited, and the strength and durability of the fixing plate are improved.
Smart Images
Figure CN222705696U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of batteries, and specifically provides a fixing plate, a battery pack and an electric device. Background Art
[0002] In electrical devices (such as electric vehicles), the battery system is one of the key systems, and its safety performance directly affects the safety of the entire vehicle. Among them, the power battery pack (hereinafter referred to as the battery pack) is the core component of the battery system.
[0003] In a battery pack, multiple power battery cells are usually stacked and connected in series or parallel to form a battery cell group. However, during the use of the battery pack, the battery cells (especially the soft-pack battery cells) may expand. In order to fix the battery cell group and limit its excessive expansion, an end plate is usually provided in the battery pack case. The battery cell group is fixed between two end plates, and the two end plates are connected by a fixing plate. However, the existing fixing plate cannot effectively limit the expansion of the battery cell. If the tension of the battery cell expansion is too large, it may cause the fixing plate to break, especially the end of the fixing plate often breaks. Utility Model Content
[0004] In order to solve the problem that the ends of the above-mentioned fixing plate often break, the utility model provides a fixing plate for connecting the lower box of the battery pack, the above-mentioned lower box includes a plurality of end plates arranged along a first direction, a battery cell group is arranged between the two end plates, the above-mentioned fixing plate includes a first section fixing plate and a second section fixing plate located at both ends of the above-mentioned first section fixing plate, and the above-mentioned second section fixing plate is used to connect with the above-mentioned end plates. The above-mentioned first section fixing plate is provided with a first groove, and the above-mentioned second section fixing plate is provided with a second groove; along the second direction perpendicular to the first direction, the dimension of the above-mentioned first groove from the first side edge of the above-mentioned first section fixing plate is L1; the dimension of the weak area of the above-mentioned second fixing plate is L2, and L1 and L2 satisfy: 1:1≤L1 / L2≤3:2.
[0005] By providing the first groove on the first section of the fixing plate and the second groove on the second section of the fixing plate, the overall stress concentration of the fixing plate can be improved. Since the local force on the second section of the fixing plate is greater than the local force on the first section of the fixing plate when the battery cell group expands, it is easier to break. Therefore, by designing the size of the weak area of the second section of the fixing plate and the size relationship between the first groove and the first side (the weak area of the first section of the fixing plate) to meet the above numerical range, the second section of the fixing plate can be prevented from breaking.
[0006] In an optional technical solution of the utility model, along the second direction, the width of the second section of the fixing plate is greater than the width of the first section of the fixing plate. By increasing the width of the second section of the fixing plate along the second direction, the stress per unit area of the second section of the fixing plate can be reduced, and the expansion of the battery cell group can be better limited while avoiding the risk of fracture.
[0007] In an optional technical solution of the utility model, the first side of the first section fixing plate is connected to the second side of the second section fixing plate, and the angle between the first side and the second side is an obtuse angle. In the case where the width of the second section fixing plate is greater than that of the first section fixing plate, if the angle between the first side and the second side is an acute angle or a right angle, the stress at the connection between the first side and the second side is highly concentrated, and it is easy to break at the connection. Designing the angle between the first side and the second side to be an obtuse angle can avoid stress concentration.
[0008] In an optional technical solution of the utility model, the second groove extends along the first direction, and the portion from the bottom of the second groove to the second side edge is the weak area. Along the second direction, the elongation of the material remains consistent, so as to avoid the external material reaching the tensile limit earlier than the internal material, and the internal stress of the material is uniform.
[0009] In the optional technical solution of the utility model, the size of the first section of the fixed plate along the second direction is L3, and L1 and L3 satisfy: 1:3≤L1 / L3≤1:4. Setting the first groove on the first section of the fixed plate can improve the stress concentration of the first section of the fixed plate, but if the size of the first groove is too large, a weak area with too small a size will be formed near the first groove. If the size of the first groove is too small, the improvement effect on stress concentration is too small. Setting L1 and L3 in the above numerical range can make the setting of the first groove effectively improve the stress concentration problem of the first section of the fixed plate, while not making the weak area around the first groove too small, thereby avoiding the first section of the fixed plate from breaking.
[0010] In an optional technical solution of the utility model, along the second direction, the second section fixing plate is provided with a plurality of the second grooves at intervals, the difference between the total width of the second section fixing plate and the width of the second groove is L4, the width of the second section fixing plate is L5, and L4 and L5 satisfy: 1:1≤L4 / L5≤2:1. The second groove is provided on the second section fixing plate to improve the stress concentration of the second section fixing plate, and L4 and L5 are designed to be within the above numerical range, which can improve the stress concentration while ensuring that the effective area around the second groove that bears the tensile force is large enough to avoid its breakage.
[0011] In an optional technical solution of the present utility model, reinforcing ribs are also provided on the first section of the fixing plate.
[0012] The utility model also provides a battery pack, including a lower box body, the lower box body includes a plurality of end plates arranged along a first direction, a battery cell group is arranged between two of the end plates, and the battery pack also includes the fixing plate, which is connected to the end plates.
[0013] In an optional technical solution of the utility model, the end plate includes a top surface and an outer side surface, and an inclined surface is further provided between the top surface and the outer side surface; an inclined third section of the fixing plate is further provided between the first section of the fixing plate and the second section of the fixing plate; the second section of the fixing plate is connected to the outer side surface, the first section of the fixing plate is supported on the top surface, and the third section of the fixing plate is arranged opposite to the inclined surface, that is, the third section of the fixing plate is arranged facing the inclined surface. By arranging the inclined surface of the end plate and the inclined third section of the fixing plate to be arranged opposite to each other, relative to a right-angle transition, stress concentration can be reduced and the fixing plate can be prevented from breaking.
[0014] In an optional technical solution of the present invention, a gap is further provided between the inclined surface and the third section fixing plate, and a size L6 of the gap and a thickness h of the third section fixing plate satisfy: 0.5h≤L6≤1.5h.
[0015] In the optional technical solution of the utility model, the angle between the third section fixing plate and the first section fixing plate is α, and the angle between the third section fixing plate and the second section fixing plate is β, and the above α and β satisfy: 120o≤α≤150o, 120o≤β≤150o. Designing α and β within the above numerical range can balance the forces on the first section fixing plate and the second section fixing plate. There is a gap between the design inclined surface and the third section fixing plate. When the battery cell expands, the pressure generated by the expansion is borne by the fixing plate to avoid bending and deformation of the end plate.
[0016] In an optional technical solution of the present invention, the battery cell group includes at least one column of multiple battery cells arranged along a first direction, a first fixing plate and a second fixing plate are arranged above the multiple battery cells, the distance between the center line of any one of the first fixing plate and the second fixing plate and the end wall of the battery cell is L7, the distance between the two end walls of the battery cell is L8, and L7 and L8 satisfy: 1 / 5≤L7 / L8≤1 / 3.
[0017] In an optional technical solution of the present utility model, the battery cell group includes a battery cell and a buffer, the battery cell includes a first surface with the largest area, and the first surface is arranged toward the end plate.
[0018] The utility model also provides an electrical device, comprising the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 A schematic diagram of a battery pack according to an embodiment of the present application;
[0020] Figure 2 A schematic diagram of a fixing plate according to an embodiment of the present application;
[0021] Figure 3A schematic diagram of another end plate and a fixing plate according to an embodiment of the present application;
[0022] Figure 4 for Figure 3 A partial enlarged view of .
[0023] Reference numerals:
[0024] Fixed plate 1;
[0025] A first section fixing plate 11 and a second section fixing plate 12;
[0026] A first groove 111, a first side 112, a second groove 121, a second side 122, and a weak area 123;
[0027] Battery pack 2;
[0028] Battery cell 21;
[0029] Lower box 3;
[0030] End plate 4;
[0031] Top surface 41 , outer side surface 42 , and inclined surface 43 . DETAILED DESCRIPTION
[0032] The following describes the optional implementations of the present invention with reference to the accompanying drawings. It should be understood by those skilled in the art that these implementations are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.
[0033] In the description of the present invention, it should be understood that the terms "distance", "width", "thickness", "up", "down", "left", "right", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying 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 direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.
[0034] In the description of the present invention, the terms "first", "second", "third", and "fourth" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0035] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, an indirect connection through an intermediate medium, or the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0036] like Figure 1 As shown, the utility model provides a fixing plate 1 and a battery pack including the same, the battery pack also includes a box body and a battery cell group 2, the box body includes a box cover and a lower box body 3, the box cover and the lower box body 3 enclose a receiving chamber for accommodating all components. The lower box body 3 further includes a plurality of end plates 4 arranged along a first direction, and the battery cell group 2 is sandwiched between two end plates 4. The fixing plate 1 includes a first section fixing plate 11 and a second section fixing plate 12 located at both ends of the first section fixing plate 11. The two second section fixing plates 12 at both ends are respectively connected to the two end plates 4 on both sides of the battery cell group to limit the expansion of the battery cell group. A first groove 111 is provided on the first section fixing plate 11, and a second groove 121 is provided on the second section fixing plate 12. Along the second direction perpendicular to the first direction, the distance between the first groove 111 and the first side edge 112 of the first section fixing plate 11 is L1, and the size of the weak area of the second section fixing plate 12 is L2, and L1 and L2 satisfy: 1:1≤L1 / L2≤3:2. By providing the first groove 111 on the first section of the fixed plate 11 and the second groove 121 on the second section of the fixed plate 12, the overall stress concentration of the fixed plate 1 can be improved. Since the local force on the second section of the fixed plate 12 is greater than the local force on the first section of the fixed plate 11 when the battery cell group expands, it is easier to break. Therefore, by designing the size of the weak area of the second section of the fixed plate 12 and the size relationship between the first groove 111 and the first side 112 (the weak area of the first section of the fixed plate) to meet the above numerical range, the second section of the fixed plate 12 can be prevented from breaking. The weak area of the second section of the fixed plate 12 is the area with the smallest size. Specifically, L1 / L2 can be 1, 1.2, 1.4, 1.5.
[0037] In an optional embodiment of the present application, the battery cell group between the two end plates 4 may include only one row of multiple battery cells arranged along the first direction, or may include multiple rows. The first section of the fixing plate 11 may also be provided with reinforcing ribs instead of the first groove 111, or both reinforcing ribs and the first groove 111 may be provided. Figure 1 The waist-shaped hole in the second slot 12 may also include a round hole, a polygonal hole, an irregular hole, etc. The structure of the second slot 12 is also not limited to Figure 1 The structure and quantity shown. Figure 1In the illustrated embodiment, only two end plates 4 are exemplarily shown in the lower box body 3. It can be understood that according to actual needs, multiple (greater than two) end plates arranged along the first direction can also be provided in the lower box body 3. These plates can limit the expansion of the battery cell group on the one hand, and can play a supporting role on the other hand, thereby improving the strength of the battery pack. For example, three end plates can be provided in the lower box body 3, that is, in addition to the two end plates 4 close to the side walls of the lower box body 3, a middle end plate (hereinafter referred to as a partition) is also provided. The partition divides the lower box body 3 into two accommodating cavities arranged along the first direction. The battery cell group is provided between the end plate 4 and the partition. A long fixed plate can be provided along the first direction to simultaneously connect the two end plates 4 and the partition, or two short fixed plates can be provided, and the two ends of the short fixed plate are respectively connected to the end plate 4 and the partition. The material of the fixed plate includes at least one of steel, aluminum and titanium alloy.
[0038] In an optional embodiment of the present application, Figure 1 As shown, along the second direction, the width of the second section fixing plate 12 is greater than the width of the first section fixing plate 11. By increasing the width of the second section fixing plate 12 along the second direction, the stress per unit area of the second section fixing plate 12 can be reduced, and the expansion of the battery cell group can be better limited while avoiding the risk of fracture.
[0039] In an optional embodiment of the present application, Figure 1 As shown, the first side 112 of the first section fixed plate 11 and the second side 122 of the second section fixed plate 12 are connected, and the angle between the first side 112 and the second side 122 is an obtuse angle. In the case where the width of the second section fixed plate 12 is greater than that of the first section fixed plate 11, if the angle between the first side 112 and the second side 122 is an acute angle or a right angle, the stress at the connection between the first side 112 and the second side 122 is highly concentrated, and it is easy to break at the connection. Designing the angle between the first side 112 and the second side 122 to be an obtuse angle can avoid stress concentration. The specific angle between the first side 112 and the second side 122 can be 115°, 120°, 130°, 140°, or 150°.
[0040] In an optional embodiment of the present application, Figure 2 As shown, the second groove 121 extends along the first direction, and the size of the second groove 121 along the first direction is designed to be larger, so the area from the bottom of the second groove 121 to the second side 122 is the weak area 123, and the size of the weak area 123 is L2. The area from the bottom of the second groove 121 to the second side 122 is the weak area of the second section of the fixing plate 12 is an embodiment of the present application, and of course, the size of the second groove 121 along the first direction can also be designed to be smaller, that is, other areas can also be the weak area of the second section of the fixing plate 12.
[0041] In an optional embodiment of the present application, Figure 1 and Figure 2As shown, the dimension of the first section fixed plate 11 along the second direction is L3, and the dimension L1 of the first groove 111 from the first side 112 of the first section fixed plate 11 and the dimension L3 of the first section fixed plate 11 along the second direction satisfy: 1:3≤L1 / L3≤1:4. The first groove 111 is provided on the first section fixed plate 11 to improve the stress concentration of the first section fixed plate 11. However, if the dimension of the first groove 111 is too large, a weak area with too small a dimension will be formed near the first groove 111. If the dimension of the first groove 111 is too small, the improvement effect on stress concentration is too small. By setting L1 and L3 within the above numerical range, the setting of the first groove 111 can effectively improve the stress concentration problem of the first section fixed plate 11 without making the weak area around the first groove 111 too small, thereby avoiding the first section fixed plate 11 from breaking.
[0042] In an optional embodiment of the present application, along the second direction, a plurality of second grooves 121 are arranged at intervals on the second section fixing plate 12, and the difference between the total width of the second section fixing plate 12 and the width of all the second grooves 121 is L4. Figure 2 As shown, two second grooves 121 are arranged at intervals on the second section fixing plate 12, and the sum of L41, L42 and L43 in the figure is the sum of the widths of the areas on both sides of all the second grooves 121. The width of the second section fixing plate 12 is L5, and L4 and L5 satisfy: 1:1≤L4 / L5≤2:1. Providing the second grooves 121 on the second section fixing plate 12 can improve the stress concentration of the second section fixing plate 12. Designing L4 and L5 within the above-mentioned numerical range can improve the stress concentration while ensuring that the effective area around the second groove 121 that withstands the tensile force is large enough to avoid its breakage.
[0043] In an optional embodiment of the present application, Figure 3 and Figure 4 As shown, the end plate 4 includes a top surface 41 and an outer side surface 42, and an inclined surface 43 is further provided between the top surface 41 and the outer side surface 42. An inclined third section fixing plate 13 is further provided between the first section fixing plate 11 and the second section fixing plate 12; the second section fixing plate 12 is connected to the outer side surface 42, the first section fixing plate 11 is supported on the top surface 41, and the third section fixing plate 13 and the inclined surface 43 are arranged opposite to each other, that is, the third section fixing plate 13 is arranged facing the inclined surface 43. By arranging the inclined surface 43 of the end plate 4 and the inclined third section fixing plate 13 of the fixing plate 1 to be arranged opposite to each other, relative to the right-angle transition, stress concentration can be reduced and the fixing plate 1 can be prevented from breaking.
[0044] In an optional embodiment of the present application, Figure 3 and Figure 4 As shown, a gap is provided between the inclined surface 43 and the third section fixing plate 13 , and the size L6 of the gap and the thickness h of the third section fixing plate 13 satisfy: 0.5h≤L6≤1.5h.
[0045] In an optional embodiment of the present application, Figure 3 and Figure 4 As shown, the angle between the third section fixing plate 13 and the first section fixing plate 11 is α, and the angle between the third section fixing plate 13 and the second section fixing plate 12 is β, and α and β satisfy: 120°≤α≤150°, 120°≤β≤150°. Designing α and β within the above numerical range can balance the forces on the first section fixing plate 11 and the second section fixing plate 12. Designing a gap between the inclined surface 43 and the third section fixing plate 13, when the battery cell expands, the pressure generated by the expansion is borne by the fixing plate 1, avoiding bending and deformation of the end plate 4.
[0046] In an optional embodiment of the present application, Figure 1 As shown, the battery cell group includes at least one column of multiple battery cells 21 arranged along the first direction, and a first fixing plate and a second fixing plate are arranged above each battery cell 21 along the second direction. The distance between the center line of any one of the first fixing plate and the second fixing plate and the end wall of the battery cell 21 is L7, and the distance between the two end walls of the battery cell 21 is L8, and L7 and L8 satisfy: 1 / 5≤L7 / L8≤1 / 3. Specifically, the battery cell group 2 includes a battery cell 21, a buffer and a liquid cooling plate, and the arrangement order of the three can be arranged in the manner of "battery cell-liquid cooling plate-battery cell-buffer-battery cell", or in the manner of "battery cell-buffer-liquid cooling plate-buffer-battery cell". In this way, the expansion of the battery cell can be resisted while taking into account the thermal management capability of the battery cell. Specifically, the battery cell includes a first surface with the largest area, and the first surface is arranged toward the end plate, and of course, other surfaces can also be arranged toward the end plate.
[0047] The utility model also provides an electric device. The electric device of the utility model includes a battery pack of an optional embodiment. By setting the battery pack, the end of the fixing belt that is prone to stress concentration can be avoided from breaking, ensuring the expansion restriction of the battery cell group. The electric device can be, but not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, and the like. Among them, the electric toy can include fixed or mobile electric toys, for example, game consoles, electric car toys, electric ship toys, electric airplane toys, and the like, and the spacecraft can include airplanes, rockets, space shuttles, spacecrafts, and the like.
[0048] So far, the technical solution of the utility model has been described in conjunction with the optional implementation modes shown in the accompanying drawings, but it is easy for those skilled in the art to understand that the protection scope of the utility model is obviously not limited to these specific implementation modes. Without departing from the principle of the utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the utility model.
Claims
1. A fixing plate for connecting a lower box of a battery pack, wherein the lower box comprises a plurality of end plates arranged along a first direction, a battery cell group is arranged between two end plates, the fixing plate comprises a first section fixing plate and a second section fixing plate located at both ends of the first section fixing plate, the second section fixing plate is used to connect with the end plates; characterized in that: The first section of the fixing plate is provided with a first groove, and the second section of the fixing plate is provided with a second groove; Along a second direction perpendicular to the first direction, a distance between the first groove and the first side edge of the first section of the fixing plate is L1; The size of the weak area of the second section fixing plate is L2, and L1 and L2 satisfy: 1:1≤L1 / L2≤3:
2.
2. The fixing plate according to claim 1, characterized in that Along the second direction, the width of the second section of the fixing plate is greater than the width of the first section of the fixing plate.
3. The fixing plate according to claim 2, characterized in that: The first side edge of the first section fixing plate is connected to the second side edge of the second section fixing plate, and the included angle between the first side edge and the second side edge is an obtuse angle.
4. The fixing plate according to claim 3, characterized in that: The second groove extends along the first direction, and the portion from the bottom of the second groove to the second side edge is the weak area.
5. The fixing plate according to claim 1, characterized in that: The dimension of the first section of the fixing plate along the second direction is L3, and L1 and L3 satisfy the following: 1:3≤L1 / L3≤1:
4.
6. The fixing plate according to claim 3, characterized in that: Along the second direction, a plurality of second grooves are arranged at intervals on the second section fixing plate.
7. The fixing plate according to claim 3, characterized in that: Along the second direction, the difference between the total width of the second section of the fixing plate and the width of the second groove is L4, the width of the second section of the fixing plate is L5, and L4 and L5 satisfy: 1:1≤L4 / L5≤2:
1.
8. The fixing plate according to claim 1, wherein: The first groove is at least one of a circular hole, a waist-shaped hole, and a polygonal hole.
9. A battery pack, comprising a lower box, the lower box comprising a plurality of end plates arranged along a first direction, a battery cell group being arranged between two of the end plates, characterized in that: The battery pack further comprises a fixing plate as claimed in any one of claims 1 to 8, wherein the fixing plate is connected to the end plate.
10. The battery pack according to claim 9, characterized in that: The end plate comprises a top surface and an outer side surface, and an inclined surface is provided between the top surface and the outer side surface; An inclined third section fixing plate is also provided between the first section fixing plate and the second section fixing plate; The second section of the fixing plate is connected to the outer side surface, and the third section of the fixing plate is arranged opposite to the inclined surface.
11. The battery pack according to claim 10, characterized in that: A gap is also provided between the third section fixing plate and the inclined surface.
12. The battery pack according to claim 11, characterized in that: The size of the gap is L6, the thickness of the third section of the fixing plate is h, and L6 and h satisfy: 0.5h≤L6≤1.5h.
13. The battery pack according to claim 10, characterized in that: The angle between the third section fixing plate and the first section fixing plate is α, the angle between the third section fixing plate and the second section fixing plate is β, and the angle α and the angle β satisfy: 120°≤α≤150°, 120°≤β≤150°.
14. The battery pack according to claim 9, characterized in that: The battery cell group includes at least one column of multiple battery cells arranged along a first direction, and a first fixing plate and a second fixing plate are arranged above the multiple battery cells. The distance between the center line of any one of the first fixing plate and the second fixing plate and the end wall of the battery cell is L7, and the distance between the two end walls of the battery cell is L8, and L7 and L8 satisfy: 1 / 5≤L7 / L8≤1 / 3.
15. The battery pack according to claim 9, characterized in that: The battery cell group includes a battery cell and a buffer. The battery cell includes a first surface with the largest area, and the first surface is arranged toward the end plate.
16. An electrical device, characterized in that: The electrical device comprises the battery pack according to any one of claims 9 to 15.