Power battery lower box body and power battery

Abstract

The utility model relates to the technical field of power batteries, and discloses a lower box body of a power battery and the power battery, the lower box body comprises a frame assembly, the frame assembly comprises a lower box body frame and transverse and longitudinal beams arranged in the lower box body frame, the lower box body frame comprises two opposite first edge beams and two opposite second edge beams, the two first edge beams are arranged between the two second edge beams and are perpendicular to the second edge beams, and the end parts of the adjacent first edge beams and the end parts of the second edge beams are fixedly connected; the water cooling plate is arranged on the bottom side of the frame assembly and is fixedly and hermetically connected with the frame assembly; the bottom protection plate is arranged on the bottom side of the water cooling plate, detachably connected with the frame assembly and hermetically connected with the water cooling plate; the outer side of each second boundary beam is provided with a mounting beam upper part, the periphery of the bottom guard plate is provided with a mounting beam lower part corresponding to the mounting beam upper part, and the mounting beam upper part is detachably connected with the mounting beam lower part. According to the lower box body, the detachability of the bottom protection plate is increased, the deformation resistance of the whole structure can be improved, the yield of the whole structure is improved, and the air tightness is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of power batteries, in particular to a power battery lower box and a power battery. Background Art

[0002] With the development of the battery application industry, there are more and more requirements for battery design. At present, in the field of power batteries, the common lower box types are mostly aluminum profile lower boxes, sheet metal stamping lower boxes, and cast aluminum lower boxes. Although these types of box structures are very mature, due to the need to reduce costs, roll-pressed boxes are gradually being used.

[0003] Among them, the power battery is installed on the vehicle body, and is generally installed on the vehicle body by setting the mounting components on the lower box frame. Due to the gravity of the lower box itself and the influence of some external extrusion loads caused by some vehicle conditions, the lower box frame is easily deformed under the load, which in turn easily leads to deformation of the overall structure of the lower box, thereby causing problems such as the yield and airtightness of the lower box structure. Utility Model Content

[0004] The purpose of the utility model is to provide a power battery lower box and a power battery, wherein the power battery lower box increases the detachability of the bottom guard plate and can improve the deformation resistance of the overall structure of the lower box, which is beneficial to improving the structural yield of the power battery lower box and ensuring good air tightness.

[0005] In order to achieve the above object, the utility model provides the following technical solutions:

[0006] A power battery lower box, comprising:

[0007] A frame assembly, the frame assembly comprising: a lower box frame, and transverse and longitudinal beams arranged in the lower box frame and fixed to the lower box frame, the lower box frame comprising: two first side beams arranged oppositely and at intervals, and two second side beams arranged oppositely and at intervals, the first side beam is perpendicular to the second side beam, the two first side beams are respectively located between the two second side beams, and the ends of the first side beam and the ends of the second side beam adjacent to each other are fixed and sealed;

[0008] A water cooling plate, disposed on the bottom side of the frame assembly, the water cooling plate being fixedly and sealingly connected to the frame assembly;

[0009] A bottom guard plate is arranged on the side of the water-cooling plate away from the frame assembly, the bottom guard plate is detachably connected to the frame assembly, and the bottom guard plate is sealed to the water-cooling plate; wherein, an upper mounting beam extending along an extension direction of the second side beam is arranged on the outer side of each second side beam, and a lower mounting beam corresponding to and cooperating with the upper mounting beam is arranged around the bottom guard plate, and the upper mounting beam and the lower mounting beam are detachably connected.

[0010] In the above-mentioned power battery lower box, the mounting beam on the side of the frame assembly is composed of an upper portion of the mounting beam connected to the frame assembly and a lower portion of the mounting beam connected to the side of the bottom guard plate. The bottom guard plate and the frame assembly jointly bear some loads after the power battery lower box is installed on the vehicle body, which effectively reduces the stress on the frame assembly and reduces the deformation risk of the frame assembly. The bottom guard plate and the frame assembly, as well as the upper portion of the mounting beam and the lower portion of the mounting beam are detachably connected, which increases the detachability of the bottom guard plate and can also help absorb part of the stress, which can effectively improve the deformation resistance of the overall structure of the power battery lower box, is beneficial to improving the structural yield of the power battery lower box, and ensures good airtightness.

[0011] Optionally, the water-cooling plate is connected to the frame assembly via rivet nuts, and the rivet nuts are provided between the water-cooling plate and the first side beam, the second side beam, and the transverse and longitudinal beams.

[0012] Optionally, a mounting hole corresponding to the position of the rivet nut is provided on the bottom guard plate, and a first bolt is passed through the mounting hole and the inner hole of the rivet nut to achieve fixed connection between the bottom guard plate and the frame assembly.

[0013] Optionally, a sealant is provided between the contact connection surfaces of the water-cooling plate and the frame assembly; and / or a sealing foam is provided between the water-cooling plate and the bottom guard plate.

[0014] Optionally, the transverse and longitudinal beams include a transverse beam and a longitudinal beam that are perpendicular to each other, and the transverse beam is arranged parallel to the first side beam.

[0015] Optionally, the lower portion of the mounting beam and the bottom guard plate have an integrated structure, the upper portion of the mounting beam is provided with a first connecting hole, the lower portion of the mounting beam is provided with a second connecting hole opposite to the first connecting hole, and the upper portion of the mounting beam and the lower portion of the mounting beam are connected by bolts and nuts passing through the first connecting hole and the second connecting hole.

[0016] Optionally, the second side beam has a first reinforcing rib in it, the first reinforcing rib is parallel to the bottom side of the second side beam, and in a direction parallel to the bottom side of the second side beam, the first reinforcing rib is opposite to the upper part of the mounting beam; and / or,

[0017] The first side beam has a second reinforcing rib in it, and the second reinforcing rib is parallel to the bottom side of the first side beam; and / or,

[0018] The transverse and longitudinal beams have third reinforcing ribs therein, and the third reinforcing ribs are parallel to the bottom sides of the transverse and longitudinal beams.

[0019] Optionally, at the connection between the first side beam and the second side beam, the end of the first side beam forms a first inclined surface structure, the end of the second side beam forms a second inclined surface structure that contacts and cooperates with the first inclined surface structure, the first inclined surface structure and the second inclined surface structure are contacted and spliced, and the first inclined surface structure and the second inclined surface structure are welded and fixed.

[0020] Optionally, the lower box frame is a roll-formed steel profile frame, and the transverse and longitudinal beams are roll-formed steel profile beams;

[0021] A first weight-reducing hole is arranged on the inner wall of the first side beam, and / or a second weight-reducing hole is arranged on the inner wall of the second side beam.

[0022] Based on the same design concept, the present solution also provides a power battery, including any power battery lower box provided by the above technical solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings constituting part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. Among them:

[0024] Figure 1 A partial exploded schematic diagram of the structure of a lower box of a power battery provided by an embodiment of the utility model;

[0025] Figure 2 A schematic diagram of the structure of a power battery lower box provided by an embodiment of the utility model;

[0026] Figure 3 for Figure 2 A schematic diagram of the structure enlargement at the center A;

[0027] Figure 4 A schematic diagram of a top view of a lower box of a power battery provided in an embodiment of the utility model;

[0028] Figure 5 for Figure 4 Schematic diagram of the cross section along the BB direction;

[0029] Figure 6 for Figure 5 Enlarged schematic diagram of the structure at C in the middle.

[0030] Icons: 1-lower box frame; 2-horizontal and longitudinal beams; 3-water cooling plate; 4-bottom guard plate; 5-mounting beam; 11-first side beam; 12-second side beam; 21-horizontal beam; 22-longitudinal beam; 51-upper part of mounting beam; 52-lower part of mounting beam; 121-first reinforcement rib. DETAILED DESCRIPTION

[0031] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments. Each example is provided by way of explanation of the present invention and does not limit the present invention. In fact, it will be clear to those skilled in the art that modifications and variations may be made in the present invention without departing from the scope or spirit of the present invention. For example, a feature shown or described as a part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desired that the present invention includes such modifications and variations within the scope of the appended claims and their equivalents.

[0032] In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention. The terms "connected", "connected" and "set" used in the present invention should be understood in a broad sense. For example, they can be fixedly connected or detachably connected; they can be directly connected or indirectly connected through an intermediate component. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0033] refer to Figure 1 and Figure 2As shown, the utility model provides a power battery lower box, including: a frame assembly, a water cooling plate 3 and a bottom guard plate 4, the frame assembly, the water cooling plate 3 and the bottom guard plate 4 are arranged and distributed in sequence along a first direction, wherein, for ease of description, the placement position of the power battery lower box is used for description, the first direction is a vertical direction, and the frame assembly, the water cooling plate 3 and the bottom guard plate 4 are arranged and connected in sequence from top to bottom. Specifically, the frame assembly includes: a lower box frame 1, and a transverse and longitudinal beam 2 arranged in the lower box frame 1 and fixed to the lower box frame 1, the lower box frame 1 includes four side beams, the four side beams are connected end to end in sequence, and two side beams adjacent to each other are spliced ​​and fixed, and sealed. Preferably, two adjacent side beams can be selected for welding, and the four side beams form a rectangular frame. The internal space inside the rectangular frame is used to accommodate batteries, the side of the side beam facing the internal space is the inner side of the side beam, and the side of the side beam away from the internal space is the outer side of the side beam; the side beam is a profile structure, specifically a profile with a rectangular cross-section, wherein the four side beams can be divided into two first side beams 11 arranged oppositely and at intervals, and two second side beams 12 arranged oppositely and at intervals, the two first side beams 11 are parallel to each other, the two second side beams 12 are parallel to each other, and the first side beam 11 and the second side beam 1 are parallel to each other. 2 is vertical, the two first side beams 11 are respectively located between the two second side beams 12, between the first side beams 11 and the second side beams 12 that are adjacent to each other, the ends of the first side beams 11 and the ends of the second side beams 12 are spliced, fixed and sealed, the two first side beams 11 can be respectively called the front side beam and the rear side beam of the lower box frame 1, the two second side beams 12 can be respectively called the left beam and the right beam of the lower box frame 1, the four side beams are fixedly connected end to end in sequence, and are sealed at the connection to form a lower box frame 1 with a firm and stable structure, the transverse and longitudinal beams 2 are located inside the lower box frame 1, and the ends of the transverse and longitudinal beams 2 are fixedly connected to the lower box frame 1, spanning the space inside the lower box frame 1, forming an effective support for the lower box frame 1 inside the lower box frame 1, which can effectively enhance the anti-extrusion ability of the lower box frame 1, so that the anti-deformation ability of the lower box frame 1 is effectively improved.

[0034] The water-cooling plate 3 is arranged on the bottom side of the frame assembly, and the water-cooling plate 3 is fixedly and sealedly connected to the frame assembly. Preferably, a sealant can be applied between the contact connection surfaces of the water-cooling plate 3 and the frame assembly to form a sealing layer, so that the water-cooling plate 3 and the frame assembly have good sealing properties.

[0035] The bottom guard plate 4 is arranged on the side of the water-cooling plate 3 away from the frame assembly, the bottom guard plate 4 is fixed to the frame assembly, and the bottom guard plate 4 and the frame assembly are arranged to be detachably connected, and the bottom guard plate 4 and the water-cooling plate 3 are sealed. Preferably, for the sealing between the bottom guard plate 4 and the water-cooling plate 3, a sealing foam can be arranged between the water-cooling plate 3 and the bottom guard plate 4. When the frame assembly and the bottom guard plate 4 are pressed and fixed, the sealing foam is clamped between the water-cooling plate 3 and the bottom guard plate 4, which has a good sealing effect. The bottom guard plate 4 is fixedly connected to the frame assembly and is arranged to be detachably connected, which increases the removability between the bottom guard plate 4 and the frame assembly. When the lower box of the power battery needs to be inspected, maintained or other conditions require the removal of the bottom guard plate 4, it is convenient to disassemble, which is conducive to improving work efficiency. Among them, in the above-mentioned lower box frame 1, a mounting beam upper portion 51 extending along the extension direction of the second side beam 12 is provided on the outer side of each second side beam 12. For example, the mounting beam upper portion 51 can be welded and fixed on the outer side of the second side beam 12. The mounting beam upper portion 51 can be connected to the outer side of the second side beam 12 by resistance spot welding, which can avoid the problems of large welding deformation and poor corrosion resistance caused by arc welding. The mounting beam upper portion 51 can be a plate-like structure extending along the extension direction of the second side beam 12; The periphery of the bottom guard plate 4 is provided with a mounting beam lower portion 52 corresponding to and matching the mounting beam upper portion 51. The mounting beam lower portion 52 can also be a plate-shaped structure extending along the side of the bottom guard plate 4, matching the corresponding mounting beam upper portion 51, wherein the mounting beam lower portion 52 is fixedly connected to the two opposite sides of the bottom guard plate 4, respectively, and the mounting beam upper portion 51 and the mounting beam lower portion 52 are detachably connected. The mounting beam upper portion 51 and the mounting beam lower portion 52 are fixedly connected, and can constitute a mounting beam 5 on the outside of the left and right beams, such as Figure 4 and Figure 5As shown, when the lower box of the power battery is installed on the vehicle body, the mounting beam 5 is used to carry the mounting part connected to the vehicle body to bear the gravity of the power battery. Since the mounting beam 5 of this embodiment is composed of the lower part 52 of the mounting beam on the bottom guard plate 4 and the upper part 51 of the mounting beam of the frame assembly, the frame assembly will not bear all the gravity loads, as well as some other extrusion loads or other forces due to installation on the vehicle body (for example, some forces on the lower box of the power battery due to vibration or other vehicle conditions), and the bottom guard plate 4 will also bear a part of it, which will reduce the force on the frame assembly and reduce the deformation risk of the frame assembly, and is conducive to improving the deformation resistance of the overall structure of the lower box of the power battery. In addition, the upper part of the mounting beam and the lower part of the mounting beam are detachably connected to ensure the connection between the lower bottom plate and the frame assembly. It is easy to disassemble. Compared with the non-detachable fixed connection method such as welding between the upper part and the lower part of the mounting beam, the damage of the welding part after the deformation under stress directly affects the structure of the lower box structure. The detachable connection method is adopted, so that the contact structure between the upper part and the lower part of the mounting beam is not connected rigidly. When subjected to external force, there is a certain room for "activity" between the two, and the welding will not destroy the structure between the two and their respective structures, thereby causing damage to the lower box structure. Moreover, the detachable connection between the two is only a contact fixation, and the stress transfer between the two is reduced, which is conducive to part of the stress being absorbed by the connecting parts, reducing the stress on the lower box structure itself, reducing the risk of the lower box structure being damaged, and is conducive to improving the structural yield of the lower box of the power battery and ensuring good air tightness.

[0036] Therefore, in the above-mentioned power battery lower box, the mounting beam on the side of the frame assembly is composed of an upper portion of the mounting beam connected to the frame assembly and a lower portion of the mounting beam connected to the side of the bottom guard plate. The bottom guard plate and the frame assembly jointly bear some loads after the power battery lower box is installed on the vehicle body, effectively reducing the stress on the frame assembly, and can effectively reduce the deformation risk of the frame assembly. The bottom guard plate and the frame assembly, as well as the upper portion of the mounting beam and the lower portion of the mounting beam are detachably connected, which increases the removability of the bottom guard plate and can also help absorb part of the stress, which can effectively improve the deformation resistance of the overall structure of the power battery lower box, thereby helping to improve the structural yield of the power battery lower box and ensure good airtightness.

[0037] In one possible implementation, reference Figure 1As shown, the water-cooling plate 3 is connected to the frame assembly by rivet nuts, and rivet nuts are provided between the water-cooling plate 3 and the first side beam 11, the second side beam 12, and the transverse and longitudinal beams 2. Along the extension direction of the first side beam 11, a plurality of rivet nuts are provided to fix the first side beam 11 and the water-cooling plate 3. Similarly, along the extension direction of the second side beam 12, a plurality of rivet nuts are provided to fix the second side beam 12 and the water-cooling plate 3. In addition, inside the frame assembly, in the extension direction of the transverse and longitudinal beams 2, a plurality of rivet nuts are provided to fix the transverse and longitudinal beams 2 and the water-cooling plate 3. The side beams and the transverse and longitudinal beams 2 in the frame assembly are fixedly connected to the water-cooling plate 3, thereby ensuring the connection stability between the lower box frame 1 and the water-cooling plate 3. The use of rivet nuts for connection and fixation can provide a fast, reliable, and low-cost connection, and has a strong bearing capacity, high connection strength, and is not easily deformed during installation, so that the connection between the water-cooling plate 3 and the frame assembly is firm and reliable.

[0038] For further reference, Figure 1 and Figure 2 As shown, in the above-mentioned power battery lower box, the water cooling plate 3 and the frame assembly are connected by a rivet nut. The rivet nut can be a rivet nut with a through hole in the middle, or the rivet nut can also be a rivet nut with a blind hole in the middle. When connecting the bottom guard plate 4 and the frame assembly, the bottom guard plate 4 and the frame assembly can be connected by a first bolt. Corresponding to the position of the rivet nut, a mounting hole corresponding to the rivet nut is provided on the bottom guard plate 4. The inner hole of the rivet nut has an internal thread, and the external thread of the first bolt can cooperate with the internal thread of the rivet nut. The first bolt fixes the bottom guard plate 4 to the frame assembly through the mounting hole and the inner hole of the rivet nut. Exemplarily, the first bolt can pass through the mounting hole and extend into the inner hole of the rivet nut, and be threadedly connected with the inner hole of the rivet nut, so that the bottom guard plate 4 is fixedly connected to the rivet nut, thereby fixing the bottom guard plate 4 to the frame assembly. It is simple and convenient, the connection is firm and reliable, and the connection is made at the rivet nut, no additional hole needs to be opened, and the installation and connection space is saved.

[0039] Specifically, Figure 1 and Figure 2As shown, in the above-mentioned power battery lower box, the horizontal and longitudinal beams 2 include a horizontal beam 21 and a longitudinal beam 22 which are perpendicular to each other, and the horizontal beam 21 is arranged in parallel with the first side beam 11. Exemplarily, two horizontal beams 21 can be arranged, one of which is arranged close to the front side beam, which can be called a side horizontal beam, and the other horizontal beam 21 is arranged in the middle of the lower box frame 1, which can be called a middle horizontal beam, and the longitudinal beam 22 is arranged in the middle of the lower box frame 1. The two ends of each horizontal beam 21 are respectively fixed to the left beam and the right beam on both sides, and the two ends of the longitudinal beam 22 can be respectively fixed to the rear beam and the side horizontal beam, and the middle horizontal beam is cross-connected with the longitudinal beam 22 in a "cross" shape, which can play a good supporting role in the lower box frame 1. Preferably, the middle horizontal beam and the longitudinal beam 22 can be a "cross" structure of an integrated structure, so that the horizontal and longitudinal beams 2 have better structural strength, which is conducive to improving the anti-deformation ability of the lower box frame 1.

[0040] As a preferred implementation, Figure 3 ,as well as Figure 5 and Figure 6 As shown, the lower part 52 of the mounting beam and the bottom guard plate 4 are set as an integrated structure, so that the structural strength of the lower part 52 of the mounting beam and the bottom guard plate 4 is better, the bearing capacity is stronger, and it is beneficial to enhance the anti-deformation ability. Preferably, the upper part 51 of the mounting beam and the lower part 52 of the mounting beam are connected by bolts and nuts, and a first connecting hole is provided in the upper part 51 of the mounting beam, and a second connecting hole corresponding to the first connecting hole is provided in the lower part 52 of the mounting beam. Between the upper part 51 of the mounting beam and the lower part 52 of the mounting beam, a second bolt is provided to pass through the first connecting hole, the second connecting hole and the nut thread to fix the upper part 51 of the mounting beam and the lower part 52 of the mounting beam, and the upper part 51 of the mounting beam and the lower part 52 of the mounting beam are firmly connected. The lower part 52 of the mounting beam and the upper part 51 of the mounting beam are connected by bolts, and the bolts can absorb at least part of the stress of the extrusion and vibration working conditions, reduce the deformation of the side beams and the transverse and longitudinal beams 2, and protect the battery cells. Furthermore, compared with welding fixation, the connection of the upper portion 51 of the mounting beam and the lower portion 52 of the mounting beam by bolts can avoid deformation caused by welding, absorb installation tolerances, and ensure the position accuracy of the mounting point.

[0041] Among them, in order to further improve the structural strength of the lower box frame, as a possible implementation method, reinforcing ribs are set in one, two or three of the first side beam 11, the second side beam 12 and the transverse and longitudinal beams 2, and the reinforcing ribs are parallel to the bottom side of the lower box frame 1.

[0042] Specifically, Figure 5 and Figure 6As shown, a first reinforcing rib 121 is provided in the second side beam 12, the first reinforcing rib 121 is parallel to the bottom side of the second side beam 12, and the cross section of the second side beam 12 perpendicular to its extension direction is in the shape of a "sun"; in addition, in the direction parallel to the bottom side of the second side beam 12, the first reinforcing rib 121 is opposite to the upper part 51 of the mounting beam, and the first reinforcing rib 121 is at the same height as the upper part 51 of the mounting beam relative to the bottom side of the second side beam 12. It should be noted that the first reinforcing rib 121 is at the same height as the upper part 51 of the mounting beam, which means that relative to the bottom side of the second side beam 12, within the allowable height deviation range, the heights of the two are considered to be the same. The position of the first reinforcing rib 121 is roughly flush with the position of the upper part 51 of the mounting beam, which is conducive to reducing the deformation of the left and right beams under extrusion conditions, so that the deformation of the left and right beams is small, and the stress on the battery cells inside the lower box is reduced.

[0043] Further, refer to Figure 1 and Figure 2 As shown, a second reinforcing rib is arranged in the first side beam 11 , and the second reinforcing rib is parallel to the bottom side of the first side beam 11 , so as to effectively enhance the structural strength of the second side beam 12 and improve the anti-deformation capability.

[0044] Furthermore, a third reinforcing rib is provided in the transverse and longitudinal beams 2 , and the third reinforcing rib is parallel to the bottom side of the transverse and longitudinal beams 2 , so as to effectively enhance the structural strength of the transverse and longitudinal beams 2 and improve the anti-deformation capability.

[0045] In one possible implementation, reference Figure 2 As shown, at the connection between the first side beam 11 and the second side beam 12, the end of the first side beam 11 forms a first inclined surface structure, the first inclined surface structure faces the corresponding end of the second side beam 12, and the end of the second side beam 12 forms a second inclined surface structure that contacts and cooperates with the first inclined surface structure, the first inclined surface structure and the second inclined surface structure are opposite to each other, and the first inclined surface structure and the second inclined surface structure are contacted and spliced, so that the connection between the first side beam 11 and the second side beam 12 is spliced ​​to form a right angle, and the first inclined surface structure and the second inclined surface structure are welded and fixed. Two beveled weldings are arranged at the connection between the first side beam 11 and the second side beam 12, which can effectively avoid the problem of poor airtightness of right-angle welding, which is conducive to ensuring good airtightness of the frame assembly.

[0046] Preferably, in order to facilitate processing and splicing, the inclination angle of the first slope structure can be set to 45°, referred to as the first 45° slope structure, and the inclination angle of the second slope structure can be set to 45°, referred to as the second 45° slope structure.

[0047] In the above-mentioned power battery lower box, if Figure 1 As shown, the lower box frame 1 is a roll-formed steel profile frame, specifically, the first side beam 11 and the second side beam 12 are roll-formed steel profile side beams, and the transverse and longitudinal beams 2 are roll-formed steel profile beams.

[0048] Specifically, refer to Figure 1 As shown, in order to reduce the weight of the lower box of the power battery, weight-reducing holes can be provided on the inner side of one or both of the first side beam 11 and the second side beam 12. For example, a plurality of first weight-reducing holes distributed at intervals are provided on the inner wall of the first side beam 11; a plurality of second weight-reducing holes distributed at intervals are provided on the inner wall of the second side beam 12, wherein the second weight-reducing holes can also serve as process holes for resistance spot welding, thereby facilitating the welding of the upper portion 51 of the mounting beam.

[0049] Preferably, a third weight-reducing hole may be provided on the side wall of the edge cross beam facing the interior of the frame assembly to further reduce the weight of the lower box body.

[0050] Based on the same design concept, this embodiment also provides a power battery, including any one of the power battery lower boxes provided in the above embodiments.

[0051] The above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. For those skilled in the art, the utility model may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A power battery lower box, characterized in that: include: A frame assembly, the frame assembly comprising: a lower box frame (1), and transverse and longitudinal beams (2) arranged in the lower box frame (1) and fixed to the lower box frame (1), the lower box frame (1) comprising: two first side beams (11) arranged opposite to each other and spaced apart, and two second side beams (12) arranged opposite to each other and spaced apart, the first side beam (11) being perpendicular to the second side beam (12), the two first side beams (11) being respectively located between the two second side beams (12), and the ends of the first side beams (11) and the ends of the second side beams (12) adjacent to each other being fixedly and sealedly connected; A water cooling plate (3) is arranged on the bottom side of the frame assembly, and the water cooling plate (3) is fixedly and sealingly connected to the frame assembly; A bottom guard plate (4) is arranged on a side of the water-cooling plate (3) away from the frame assembly, the bottom guard plate (4) is detachably connected to the frame assembly, and the bottom guard plate (4) and the water-cooling plate (3) are sealed; wherein, the outer side of each second side beam (12) is provided with a mounting beam upper portion (51) extending along the extension direction of the second side beam (12), and the periphery of the bottom guard plate (4) is provided with a mounting beam lower portion (52) corresponding to and matching the mounting beam upper portion (51), and the mounting beam upper portion (51) and the mounting beam lower portion (52) are detachably connected.

2. The power battery lower box according to claim 1, characterized in that: The water cooling plate (3) and the frame assembly are connected via rivet nuts, and the rivet nuts are provided between the water cooling plate (3) and the first side beam (11), the second side beam (12), and the transverse and longitudinal beams (2).

3. The power battery lower box according to claim 2, characterized in that: The bottom guard plate (4) is provided with a mounting hole corresponding to the position of the rivet nut, and a first bolt is passed through the mounting hole and the inner hole of the rivet nut to achieve fixed connection between the bottom guard plate (4) and the frame assembly.

4. The power battery lower box according to claim 1, characterized in that: A sealant is provided between the contact connection surfaces of the water cooling plate (3) and the frame assembly; and / or a sealing foam is provided between the water cooling plate (3) and the bottom guard plate (4).

5. The power battery lower box according to claim 1, characterized in that: The transverse and longitudinal beams (2) comprise a transverse beam (21) and a longitudinal beam (22) which are perpendicular to each other, and the transverse beam (21) is arranged parallel to the first side beam (11).

6. The power battery lower box according to claim 1, characterized in that: The mounting beam lower portion (52) and the bottom guard plate (4) have an integrated structure, the mounting beam upper portion (51) is provided with a first connection hole, the mounting beam lower portion (52) is provided with a second connection hole opposite to the first connection hole, and the mounting beam upper portion (51) and the mounting beam lower portion (52) are connected by bolts and nuts passing through the first connection hole and the second connection hole.

7. The power battery lower box according to any one of claims 1 to 6, characterized in that: The second side beam (12) has a first reinforcing rib (121) therein, the first reinforcing rib (121) is parallel to the bottom side of the second side beam (12), and in a direction parallel to the bottom side of the second side beam (12), the first reinforcing rib (121) is opposite to the upper portion (51) of the mounting beam; and / or, The first side beam (11) has a second reinforcing rib in it, the second reinforcing rib being parallel to the bottom side of the first side beam (11); and / or, The transverse and longitudinal beams (2) have third reinforcing ribs in them, and the third reinforcing ribs are parallel to the bottom sides of the transverse and longitudinal beams (2).

8. The power battery lower box according to any one of claims 1 to 6, characterized in that: At the connection between the first side beam (11) and the second side beam (12), the end of the first side beam (11) forms a first inclined surface structure, the end of the second side beam (12) forms a second inclined surface structure that contacts and cooperates with the first inclined surface structure, the first inclined surface structure and the second inclined surface structure are contact-jointed, and the first inclined surface structure and the second inclined surface structure are fixed by welding.

9. The power battery lower box according to any one of claims 1 to 6, characterized in that: The lower box frame (1) is a roll-formed steel profile frame, and the transverse and longitudinal beams (2) are roll-formed steel profile beams; A first weight-reducing hole is provided on the inner wall of the first side beam (11), and / or a second weight-reducing hole is provided on the inner wall of the second side beam (12).

10. A power battery, characterized in that: It comprises a power battery lower box as described in any one of claims 1 to 9.

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